<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE article PUBLIC "-//NLM//DTD Journal Publishing DTD v2.3 20070202//EN" "journalpublishing.dtd">
<article xml:lang="EN" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" article-type="research-article">
<front>
<journal-meta>
<journal-id journal-id-type="publisher-id">Front. Psychol.</journal-id>
<journal-title>Frontiers in Psychology</journal-title>
<abbrev-journal-title abbrev-type="pubmed">Front. Psychol.</abbrev-journal-title>
<issn pub-type="epub">1664-1078</issn>
<publisher>
<publisher-name>Frontiers Media S.A.</publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.3389/fpsyg.2021.774333</article-id>
<article-categories>
<subj-group subj-group-type="heading">
<subject>Psychology</subject>
<subj-group>
<subject>Original Research</subject>
</subj-group>
</subj-group>
</article-categories>
<title-group>
<article-title>Nature Interest Scale &#x2013; Development and Evaluation of a Measurement Instrument for Individual Interest in Nature</article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author" corresp="yes">
<name><surname>Kleespies</surname> <given-names>Matthias Winfried</given-names></name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<xref ref-type="corresp" rid="c001"><sup>&#x002A;</sup></xref>
<uri xlink:href="http://loop.frontiersin.org/people/844474/overview"/>
</contrib>
<contrib contrib-type="author">
<name><surname>Doderer</surname> <given-names>Lena</given-names></name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
</contrib>
<contrib contrib-type="author">
<name><surname>Dierkes</surname> <given-names>Paul Wilhelm</given-names></name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<uri xlink:href="http://loop.frontiersin.org/people/918364/overview"/>
</contrib>
<contrib contrib-type="author">
<name><surname>Wenzel</surname> <given-names>Volker</given-names></name>
<xref ref-type="aff" rid="aff2"><sup>2</sup></xref>
<uri xlink:href="http://loop.frontiersin.org/people/1486299/overview"/>
</contrib>
</contrib-group>
<aff id="aff1"><sup>1</sup><institution>Department of Biology, Bioscience Education and Zoo Biology, Goethe University Frankfurt</institution>, <addr-line>Frankfurt</addr-line>, <country>Germany</country></aff>
<aff id="aff2"><sup>2</sup><institution>Department of Biology, Bioscience Education, Goethe University Frankfurt</institution>, <addr-line>Frankfurt</addr-line>, <country>Germany</country></aff>
<author-notes>
<fn fn-type="edited-by"><p>Edited by: Edward Edgerton, University of the West of Scotland, United Kingdom</p></fn>
<fn fn-type="edited-by"><p>Reviewed by: Tim J. Croudace, University of Dundee, United Kingdom; Kathy Ellen Green, University of Denver, United States</p></fn>
<corresp id="c001">&#x002A;Correspondence: Matthias Winfried Kleespies, <email>kleespies@em.uni-frankfurt.de</email></corresp>
<fn fn-type="other" id="fn004"><p>This article was submitted to Environmental Psychology, a section of the journal Frontiers in Psychology</p></fn>
</author-notes>
<pub-date pub-type="epub">
<day>29</day>
<month>11</month>
<year>2021</year>
</pub-date>
<pub-date pub-type="collection">
<year>2021</year>
</pub-date>
<volume>12</volume>
<elocation-id>774333</elocation-id>
<history>
<date date-type="received">
<day>11</day>
<month>09</month>
<year>2021</year>
</date>
<date date-type="accepted">
<day>09</day>
<month>11</month>
<year>2021</year>
</date>
</history>
<permissions>
<copyright-statement>Copyright &#x00A9; 2021 Kleespies, Doderer, Dierkes and Wenzel.</copyright-statement>
<copyright-year>2021</copyright-year>
<copyright-holder>Kleespies, Doderer, Dierkes and Wenzel</copyright-holder>
<license xlink:href="http://creativecommons.org/licenses/by/4.0/"><p>This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.</p></license>
</permissions>
<abstract>
<p>Interest is an important factor for successful learning that has been the subject of intensive research for decades. Although interest in nature is of great importance for environmental education, to date there is no valid and reliable measurement tool. Therefore, the purpose of this study was to develop and test a scale for interest in nature, the Nature Interest Scale (NIS). In study 1, nine items were selected based on the three dimensions of the psychological interest construct to represent interest in nature. The factor structure of this new measurement instrument, was tested using confirmatory factor analyses. The results show that the instrument represents the three dimensions of the interest construct well. In study 2 the validity (discriminant and convergent validity) as well as the reliability (internal consistency, composite reliability, test-retest reliability) of the NIS were demonstrated. In study 3, the applicability of the NIS was tested with a different target group, students with learning disabilities. The results of this factor analysis also confirm the factor structure of the scale. Thus, this study provides a valid and reliable measurement tool for individual interest in nature that can be used for future research.</p>
</abstract>
<kwd-group>
<kwd>Nature Interest Scale (NIS)</kwd>
<kwd>individual interest</kwd>
<kwd>interest in nature</kwd>
<kwd>scale development</kwd>
<kwd>validity</kwd>
<kwd>reliability</kwd>
<kwd>university students</kwd>
<kwd>special needs students</kwd>
</kwd-group>
<counts>
<fig-count count="1"/>
<table-count count="4"/>
<equation-count count="2"/>
<ref-count count="83"/>
<page-count count="9"/>
<word-count count="8413"/>
</counts>
</article-meta>
</front>
<body>
<sec sec-type="intro" id="S1">
<title>Introduction</title>
<p>In everyday language, &#x201C;interest&#x201D; is often seen as motivation to learn more about a topic. Interest has also been an important topic in pedagogy and educational research for a long time: For example, the educator Dewey recognized the importance of interest more than 100 years ago (<xref ref-type="bibr" rid="B19">Dewey, 1913</xref>). Since that time, research on interest has evolved significantly. In particular, the examination of the construct of interest by researchers such as <xref ref-type="bibr" rid="B73">Schiefele (1991)</xref>, <xref ref-type="bibr" rid="B60">Prenzel (1992)</xref>, <xref ref-type="bibr" rid="B45">Krapp (1999)</xref> has greatly advanced research in recent decades.</p>
<p>Interest in educational psychology is often described as a dynamic relationship between a person and an object of interest (Person-Object-Theory of Interest; <xref ref-type="bibr" rid="B44">Krapp, 1993</xref>, <xref ref-type="bibr" rid="B42">1998</xref>, <xref ref-type="bibr" rid="B46">2000</xref>). Such an object of interest can be, for example, a topic, an idea, an activity, an event or some other content of a person&#x2019;s cognitive life space (<xref ref-type="bibr" rid="B47">Krapp, 2002</xref>).</p>
<p>Interest has been studied very intensively in the last decades and is considered a very important factor in the context of learning (<xref ref-type="bibr" rid="B64">Renninger and Hidi, 2011</xref>). Thus, interest correlates positively with learning and thereby promotes a deeper form of understanding (<xref ref-type="bibr" rid="B72">Schiefele and Schreyer, 1994</xref>). <xref ref-type="bibr" rid="B4">Ainley et al. (2002)</xref> demonstrated that both individual interest and text titles influence learning. Interest is also crucial for the way we process information and has a positive influence on cognitive functions (<xref ref-type="bibr" rid="B30">Hidi, 1990</xref>). As a result, higher interest also helps to focus on tasks and to complete them (<xref ref-type="bibr" rid="B65">Renninger et al., 2002</xref>). Overall, interest in a subject is a good basis for a better learning success (<xref ref-type="bibr" rid="B4">Ainley et al., 2002</xref>).</p>
<p>Especially in the school and academic context, the positive effects of interest become apparent. For instance, interest in a subject is a particularly important criterion when it comes to choosing a course. In high school, natural sciences courses in particular are more likely to be chosen by students who are also more interested in natural science (<xref ref-type="bibr" rid="B7">B&#x00F8;e, 2012</xref>). Physics, for example, is chosen both as a course at school and as a subject of study at university primarily by people who have an intrinsic interest in the subject (<xref ref-type="bibr" rid="B8">B&#x00F8;e and Henriksen, 2013</xref>). Similar results have been documented for mathematics (<xref ref-type="bibr" rid="B41">K&#x00F6;ller et al., 2000</xref>, <xref ref-type="bibr" rid="B40">2001</xref>). In a longitudinal study, <xref ref-type="bibr" rid="B27">Harackiewicz et al. (2002)</xref> demonstrated that university students&#x2019; interest in the introductory course was strongly correlated with subsequent course enrollment and academic major over a period of 4&#x2013;7 years.</p>
<p>Consequently, interest is directly related to academic success. Thus, interest has been shown to correlate with performance in a subject (<xref ref-type="bibr" rid="B43">Krapp, 1992</xref>) and interest in a discipline generally leads to better academic results in that area (<xref ref-type="bibr" rid="B18">Denissen et al., 2007</xref>). A performance-enhancing effect due to interest can also be assumed (<xref ref-type="bibr" rid="B43">Krapp, 1992</xref>). In a meta-study that examined a total of 121 studies from 18 countries, <xref ref-type="bibr" rid="B71">Schiefele et al. (1992)</xref> found an average correlation value of <italic>r</italic> = 0.31 between interest and academic success, demonstrating the positive connection between both factors. These research findings demonstrate the importance of interest in relation to learning and learning success.</p>
<p>In terms of structure, two basic types of interest are usually distinguished in the current literature (<xref ref-type="bibr" rid="B43">Krapp, 1992</xref>; <xref ref-type="bibr" rid="B29">Hidi et al., 2004</xref>; <xref ref-type="bibr" rid="B74">Schiefele, 2012</xref>): individual or personal interest on the one hand, and situational interest on the other. Situational interest is a motivated state that results from the stimulus of a specific learning situation (<xref ref-type="bibr" rid="B43">Krapp, 1992</xref>). Over time, situational interest may develop into a durable and stable individual interest through repeated engagement with the object of interest. Personality-specific individual interest is characterized by a dispositional internalization of a person&#x2019;s interest in an object of interest. The person-object engagement can then occur of its own accord without external triggers or support (<xref ref-type="bibr" rid="B32">Hidi and Anderson, 1992</xref>; <xref ref-type="bibr" rid="B63">Renninger and Hidi, 2002</xref>; <xref ref-type="bibr" rid="B33">Hidi and Renninger, 2006</xref>; <xref ref-type="bibr" rid="B58">Pawek, 2009</xref>; <xref ref-type="bibr" rid="B3">Ainley, 2017</xref>). In this study, special attention will be paid to longer-term individual interest.</p>
<p>Individual interest is formed of three components: An emotional, a value-related, and a cognitive component (<xref ref-type="bibr" rid="B61">Prenzel et al., 1986</xref>; <xref ref-type="bibr" rid="B31">Hidi, 2006</xref>; <xref ref-type="bibr" rid="B3">Ainley, 2017</xref>). The emotional component can be summarized as pleasant or perceived positive feelings that occur when engaging with the object of interest (<xref ref-type="bibr" rid="B47">Krapp, 2002</xref>). The cognitive component of interest is the desire to expand and develop knowledge about the object of interest and learn more about it (<xref ref-type="bibr" rid="B58">Pawek, 2009</xref>). The third component is value-related and expresses that a high personal importance and appreciation is attached to the object of interest (<xref ref-type="bibr" rid="B61">Prenzel et al., 1986</xref>; <xref ref-type="bibr" rid="B48">Krapp and Prenzel, 2011</xref>).</p>
<p>In the biology education literature numerous attempts to survey interest have been made (<xref ref-type="bibr" rid="B68">Rowland et al., 2019</xref>). Empirically investigating the construct of interest with adequate measurement instruments offers many opportunities for scientific research: For example, scientific theories and constructs can be empirically confirmed or rejected and educational programs can also be evaluated. However, the surveys of interest in the biology education literature are often with theoretical and methodological limitations. For example, many interest studies in biology education do not adequately define interest, do not consider the theory of interest, or only cover parts of the construct (<xref ref-type="bibr" rid="B68">Rowland et al., 2019</xref>).</p>
<p>Although there are a few general instruments for measuring interest in science topics that have been designed with great emphasis on meeting quality criteria (e.g., <xref ref-type="bibr" rid="B66">Romine et al., 2014</xref>; <xref ref-type="bibr" rid="B67">Rotgans, 2015</xref>), these instruments are usually either target group-dependent or topic-specific. As a result, validated measurement instrument for specific topics, such as interest in nature, are rare. To examine whether a validated and established measurement tool for interest in nature already exists in the literature, we searched the scientific database Education Resources Information Center (ERIC). The search keywords used were &#x201C;interest in nature.&#x201D; Although we found some publications that tried to empirically measure interest in nature (e.g., <xref ref-type="bibr" rid="B77">Sj&#x00F6;blom and Wolff, 2017</xref>; <xref ref-type="bibr" rid="B57">Palmberg et al., 2019</xref>; <xref ref-type="bibr" rid="B2">Ahnesj&#x00F6; and Danielsson, 2020</xref>), no validated instrument covering the three dimensions of the psychological construct of interest was found. In most cases, these were single item measurement instruments. This leads to a research gap in environmental education research and environmental psychology on the topic of interest in nature. Therefore, this study will develop, test, and evaluate a new measurement instrument for surveying interest in nature based on interest theory: The Nature Interest Scale (NIS). The development of a new scale is a multilevel process through which the quality of the new instrument is to be ensured (<xref ref-type="bibr" rid="B6">Boateng et al., 2018</xref>; <xref ref-type="bibr" rid="B15">Carpenter, 2018</xref>).</p>
<p>In study 1, appropriate items for measuring interest in nature were selected on the basis of the interest construct. The factor structure of these items was then examined with confirmatory factor analyses (CFA). In study 2, the validity and reliability of the measurement instrument were explored. The third study examined whether the factor structure observed in Study 1 is also found for another target group, namely students with special needs.</p>
</sec>
<sec id="S2">
<title>Study 1</title>
<p>In Study 1, nine items were selected based on the interest construct and then the factor structure of the new measurement instrument was examined using a CFA. A CFA is a common tool used when developing an instrument to examine the dimensionality of a scale and the relationship of items to each other (<xref ref-type="bibr" rid="B10">Brown, 2015</xref>). The advantage over a principle component analysis (PCA) is that with a CFA, the researcher has the ability to specify the factors and structure to fit the theory of the construct (<xref ref-type="bibr" rid="B83">Worthington and Whittaker, 2006</xref>).</p>
<sec id="S2.SS1">
<title>Methods</title>
<p>In order to guarantee the content validity of an instrument, it must represent as accurately as possible the concept that it is intended to capture (<xref ref-type="bibr" rid="B69">Rusticus, 2014</xref>). Therefore, according to the three components of the construct of interest, nine appropriate items were created. The items were either directly based on the definition of interest (<xref ref-type="bibr" rid="B61">Prenzel et al., 1986</xref>; <xref ref-type="bibr" rid="B31">Hidi, 2006</xref>; <xref ref-type="bibr" rid="B3">Ainley, 2017</xref>) or on previous interest studies on other topics (<xref ref-type="bibr" rid="B25">Frey et al., 2009</xref>; <xref ref-type="bibr" rid="B34">Holstermann, 2009</xref>; <xref ref-type="bibr" rid="B58">Pawek, 2009</xref>; <xref ref-type="bibr" rid="B80">Wenzel, 2016</xref>). All items were adapted to the study object &#x201C;interest in nature.&#x201D; A complete item documentation can be found in <xref ref-type="table" rid="T1">Table 1</xref>. The three components of the interest construct [emotional (EMO), cognitive (COG), and value-related (VALUE) component] were addressed with three items each which is considered to be the minimum number per factor (<xref ref-type="bibr" rid="B62">Raubenheimer, 2004</xref>).</p>
<table-wrap position="float" id="T1">
<label>TABLE 1</label>
<caption><p>The nine items selected based on the construct of interest.</p></caption>
<table cellspacing="5" cellpadding="5" frame="hsides" rules="groups">
<thead>
<tr>
<td valign="top" align="left"><bold>Abbreviation</bold></td>
<td valign="top" align="left"><bold>Item</bold></td>
<td valign="top" align="left"><bold>Explanation for content validity</bold></td>
<td valign="top" align="left"><bold>Origin of the item</bold></td>
</tr>
</thead>
<tbody>
<tr>
<td valign="top" align="left">EMO_1</td>
<td valign="top" align="left">I find it exciting to deal with nature</td>
<td valign="top" align="left">&#x201C;Exciting&#x201D; as a positive feeling</td>
<td valign="top" align="left">(<xref ref-type="bibr" rid="B25">Frey et al., 2009</xref>) I find the content really exciting</td>
</tr>
<tr>
<td valign="top" align="left">EMO_2</td>
<td valign="top" align="left">Learning about nature is fun for me</td>
<td valign="top" align="left">&#x201C;Fun&#x201D; as a positive feeling</td>
<td valign="top" align="left">(<xref ref-type="bibr" rid="B53">Mang et al., 2018</xref>) Learning mathematics is simply fun for me</td>
</tr>
<tr>
<td valign="top" align="left">EMO_3</td>
<td valign="top" align="left">When I am engaged in nature, I am very concentrated and forget everything around me</td>
<td valign="top" align="left">If someone is so intensively involved with a subject, the person must also associate positive feelings with it</td>
<td valign="top" align="left">(<xref ref-type="bibr" rid="B52">Mang et al., 2019</xref>) I quickly forget the time when I use digital devices</td>
</tr>
<tr>
<td valign="top" align="left">COG_1</td>
<td valign="top" align="left">I would like to know much more about nature</td>
<td valign="top" align="left">Desire to obtain more knowledge</td>
<td valign="top" align="left">(<xref ref-type="bibr" rid="B80">Wenzel, 2016</xref>) I would like to know more about some topics</td>
</tr>
<tr>
<td valign="top" align="left">COG_2</td>
<td valign="top" align="left">I would like to learn more about nature</td>
<td valign="top" align="left">Desire to obtain more knowledge</td>
<td valign="top" align="left">(<xref ref-type="bibr" rid="B58">Pawek, 2009</xref>) I would like to learn more about the experiments [&#x2026;]</td>
</tr>
<tr>
<td valign="top" align="left">COG_3</td>
<td valign="top" align="left">In my free time I often deal with topics related to nature</td>
<td valign="top" align="left">Wanting to spend free time on a subject implies that there is a desire to know more</td>
<td valign="top" align="left">(<xref ref-type="bibr" rid="B34">Holstermann, 2009</xref>) In my free time, I also deal with the structure of the heart</td>
</tr>
<tr>
<td valign="top" align="left">VALUE_1</td>
<td valign="top" align="left">I find it meaningful to be involved with nature</td>
<td valign="top" align="left">&#x201C;Meaningful&#x201D; assigns a personal value to nature</td>
<td valign="top" align="left">(<xref ref-type="bibr" rid="B80">Wenzel, 2016</xref>) I find it meaningful to be involved with animals</td>
</tr>
<tr>
<td valign="top" align="left">VALUE_2</td>
<td valign="top" align="left">I think it&#x2019;s important to be well informed about nature</td>
<td valign="top" align="left">&#x201C;Important&#x201D; assigns a personal value to nature</td>
<td valign="top" align="left">(<xref ref-type="bibr" rid="B80">Wenzel, 2016</xref>) I think it&#x2019;s important to be well informed about animals</td>
</tr>
<tr>
<td valign="top" align="left">VALUE_3</td>
<td valign="top" align="left">The subject of nature is important to me</td>
<td valign="top" align="left">&#x201C;Important to me&#x201D; assign a value to nature</td>
<td valign="top" align="left">(<xref ref-type="bibr" rid="B34">Holstermann, 2009</xref>) To understand the function of the heart is important to me</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn><p><italic>The last column shows the origin and the English translation of each item. The items were adapted by the authors to the topic &#x201C;interest in nature&#x201D; and partly modified.</italic></p></fn>
</table-wrap-foot>
</table-wrap>
<sec id="S2.SS1.SSS1">
<title>Participants</title>
<p>A total of 688 persons (66.71% female, 31.98% male, 1.31% no answer) were surveyed. Of these, 360 were students at Goethe University in Frankfurt. The survey took place in different courses of the Faculty of Biology. The questionnaire was handed out at the beginning of the class with the request to leave the completed survey at a collection point in the lecture room at the end of the class. Participants were informed prior to the survey about the project objectives and that participation was voluntary. The remaining 328 people were surveyed using an online questionnaire. Participants were recruited through email, personal contacts, and social networks. In the introductory text of the online survey, the participants were informed about the project objectives and data protection.</p>
</sec>
<sec id="S2.SS1.SSS2">
<title>Analysis</title>
<p>The CFA was performed using AMOS 27. Missing values were replaced by series means and maximum likelihood estimation was used as fitting function. Common fit indices were selected to test model goodness of fit (<xref ref-type="bibr" rid="B6">Boateng et al., 2018</xref>). Chi-square test (&#x03C7;<sup>2</sup>), Chi square/degrees of freedom (&#x03C7;<sup>2</sup>/df), Root Mean Squared Error of Approximation (RMSEA), Tucker Lewis Index (TLI), Comparative Fit Index (CFI), and Standardized Root Mean Square Residual (SRMR).</p>
<p>Two different models were tested. In Model 1, all interest items were attributed to a single latent factor. This view is based on prior research in which interest was often treated as a unidimensional construct (<xref ref-type="bibr" rid="B67">Rotgans, 2015</xref>; <xref ref-type="bibr" rid="B68">Rowland et al., 2019</xref>). In Model 2, the interest items were assigned to three latent factors. This was based on the literature on the interest construct (<xref ref-type="bibr" rid="B61">Prenzel et al., 1986</xref>; <xref ref-type="bibr" rid="B47">Krapp, 2002</xref>; <xref ref-type="fig" rid="F1">Figure 1</xref>).</p>
<fig id="F1" position="float">
<label>FIGURE 1</label>
<caption><p>Path diagram showing the standardized results of the confirmatory factor analysis of model 2. The values between the three factors are correlations. The values between the factors and items are standardized regression weights.</p></caption>
<graphic mimetype="image" mime-subtype="tiff" xlink:href="fpsyg-12-774333-g001.tif"/>
</fig>
</sec>
</sec>
<sec id="S2.SS2">
<title>Results</title>
<p>The CFA revealed a high correlation between the three higher-order factors of the construct of interest (&#x003E;0.7). The regression weights are also high for all items (&#x003E;0.5), with an average of 0.75 (<xref ref-type="fig" rid="F1">Figure 1</xref>). The fit indices differ slightly between the two models. However, Model 2 obtained slightly better values for all indices. The exact fit indices for both models can be found in <xref ref-type="table" rid="T2">Table 2</xref>.</p>
<table-wrap position="float" id="T2">
<label>TABLE 2</label>
<caption><p>Results CFA for models 1 and 2.</p></caption>
<table cellspacing="5" cellpadding="5" frame="hsides" rules="groups">
<thead>
<tr>
<td valign="top" align="left"></td>
<td valign="top" align="center"><bold>&#x03C7; <sup>2</sup></bold></td>
<td valign="top" align="center"><bold><italic>p</italic></bold></td>
<td valign="top" align="center"><bold>df</bold></td>
<td valign="top" align="center"><bold>&#x03C7; <sup>2</sup>/df</bold></td>
<td valign="top" align="center"><bold>CFI</bold></td>
<td valign="top" align="center"><bold>TLI</bold></td>
<td valign="top" align="center"><bold>SRMR</bold></td>
<td valign="top" align="center"><bold>RMSEA</bold></td>
</tr>
</thead>
<tbody>
<tr>
<td valign="top" align="left">Model 1</td>
<td valign="top" align="center">196.60</td>
<td valign="top" align="center">&#x003C;0.001</td>
<td valign="top" align="center">27</td>
<td valign="top" align="center">7.282</td>
<td valign="top" align="center">0.952</td>
<td valign="top" align="center">0.935</td>
<td valign="top" align="center">0.034</td>
<td valign="top" align="center">0.096</td>
</tr>
<tr>
<td valign="top" align="left">Model 2</td>
<td valign="top" align="center">115.80</td>
<td valign="top" align="center">&#x003C;0.001</td>
<td valign="top" align="center">24</td>
<td valign="top" align="center">4.825</td>
<td valign="top" align="center">0.974</td>
<td valign="top" align="center">0.961</td>
<td valign="top" align="center">0.032</td>
<td valign="top" align="center">0.075</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn><p><italic>Both models used the same sample of 688 participants.</italic></p></fn>
</table-wrap-foot>
</table-wrap>
</sec>
<sec id="S2.SS3">
<title>Discussion</title>
<p>In previous studies in which the construct of interest was measured, the factor structure of the instruments was treated differently: For example, some studies that surveyed the different aspects of the interest construct treated them as different factors (<xref ref-type="bibr" rid="B50">Linnenbrink-Garcia et al., 2010</xref>; <xref ref-type="bibr" rid="B35">Holstermann et al., 2012</xref>). In contrast, other research that also cover the different aspects of the construct treat their instruments unidimensional (<xref ref-type="bibr" rid="B70">Schiefele, 1990</xref>; <xref ref-type="bibr" rid="B75">Schiefele and Krapp, 1996</xref>; <xref ref-type="bibr" rid="B39">Kleespies et al., 2021</xref>). For a very thorough review on this topic, we recommend <xref ref-type="bibr" rid="B68">Rowland et al. (2019)</xref>. To assess whether the NIS is rather unidimensional (Model 1) or multidimensional (Model 2), different fit indices were used to evaluate the models.</p>
<p>Since the significance of the Chi-square test depends strongly on the sample size (<xref ref-type="bibr" rid="B54">Marsh et al., 1988</xref>), other indices are now often used. There are no exact guidelines for the assessment of these fit indices, only rules of thumb to help in the evaluation of models. For example, the &#x03C7;<sup>2</sup>/df ratio should be less than 5 for a sufficient model fit (<xref ref-type="bibr" rid="B81">Wheaton et al., 1977</xref>). <xref ref-type="bibr" rid="B36">Hu and Bentler (1999)</xref> recommend values close to 0.95 for the TLI and CFI, values around 0.08 for the SRMR, and values close to 0.06 for the RMSEA. However, there are also scientists who set the cutoff values slightly lower. Thus, for CFI and TLI, values greater than 0.90 may still be within the acceptable range (<xref ref-type="bibr" rid="B11">Browne and Cudeck, 1992</xref>; <xref ref-type="bibr" rid="B5">Awang, 2015</xref>), and for RMSEA values up to 0.08 or 0.10 can be tolerated (<xref ref-type="bibr" rid="B11">Browne and Cudeck, 1992</xref>; <xref ref-type="bibr" rid="B51">MacCallum et al., 1996</xref>; <xref ref-type="bibr" rid="B5">Awang, 2015</xref>).</p>
<p>Both models show a reasonable model fit. However, in a direct comparison, Model 2 shows a better model fit than Model 1. Especially the &#x03C7;<sup>2</sup>/df and the RMSEA show differences in favor of Model 2. Therefore, the results of the CFA suggest that the NIS consists of an emotional, value-related and cognitive factor. This makes it one of the few measurement instruments in the biology education literature that is based on the theoretical construct of interest and also measures this construct multidimensionally (<xref ref-type="bibr" rid="B68">Rowland et al., 2019</xref>).</p>
</sec>
</sec>
<sec id="S3">
<title>Study 2</title>
<p>After the factor structure of the newly developed test instrument was examined in study 1, the reliability and validity of the items will be tested in study 2. To test for validity, discriminant and convergent validity were examined. To examine reliability, Cronbach&#x2019;s alpha, composite reliability was calculated and test-retest reliability of the three subscales was examined.</p>
<sec id="S3.SS1">
<title>Methods</title>
<sec id="S3.SS1.SSS1">
<title>Procedure and Participants</title>
<sec id="S3.SS1.SSS1.Px1">
<title>Convergent and discriminant validity</title>
<p>To test the convergent validity of the NIS, it was compared to another interest measurement instrument, the Individual Interest Questionnaire (IIQ) by <xref ref-type="bibr" rid="B67">Rotgans (2015)</xref>. Instead of interest in biochemistry, as in the original instrument, we asked about interest in nature. Since our survey groups were not high school students, one question was excluded in the process, as it asked about interest in school lessons on the topic. The same 360 biology students that were surveyed in study 1 served as the survey group.</p>
<p>To test discriminant validity, the NIS was contrasted with four questions that asked people to rate the benefits of nature to humans based on ecosystem services (<xref ref-type="table" rid="T3">Table 3</xref>). While these measurement questions are also related to nature, the assessment should not be directly related to interest in nature. A comparatively low correlation would therefore give indications of discriminant validity. The survey group used for this purpose was the people in the online survey from study 1.</p>
<table-wrap position="float" id="T3">
<label>TABLE 3</label>
<caption><p>Questions for testing discriminant validity.</p></caption>
<table cellspacing="5" cellpadding="5" frame="hsides" rules="groups">
<thead>
<tr>
<td valign="top" align="left"></td>
<td valign="top" align="left"><bold>Ecosystem services (ES)</bold></td>
</tr>
</thead>
<tbody>
<tr>
<td valign="top" align="left">1</td>
<td valign="top" align="left">Nature has a benefit because it regulates processes such as the climate, the degradation of pollutants or the pollination of plants</td>
</tr>
<tr>
<td valign="top" align="left">2</td>
<td valign="top" align="left">Nature has a benefit in that it provides food, water, raw materials, etc., for humans</td>
</tr>
<tr>
<td valign="top" align="left">3</td>
<td valign="top" align="left">Nature has value because it is responsible for processes such as recycling of nutrients, soil formation or production of biomass</td>
</tr>
<tr>
<td valign="top" align="left">4</td>
<td valign="top" align="left">Nature has meaning as it can serve as a place for recreation or spiritual experiences</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn><p><italic>Since these questions do not measure a construct related to interest, there should be very little correlation between the constructs.</italic></p></fn>
</table-wrap-foot>
</table-wrap>
</sec>
<sec id="S3.SS1.SSS1.Px2">
<title>Test-retest reliability</title>
<p>To determine the minimum sample size for the test-retest reliability, a power analysis with GPower (<xref ref-type="bibr" rid="B21">Faul et al., 2009</xref>) was performed. For a large effect (<italic>r</italic> = 0.7), which can be expected for test-retest reliability and a power of 0.95 (two tailed test, alpha = 0.05), there must be at least a sample size of 20 participants.</p>
<p>Therefore, 50 students who had taken a course in biology at the Goethe University in Frankfurt were surveyed at the beginning of the summer semester 2021 using an online questionnaire. The students were informed about the voluntary nature of their participation and the objectives of the study. Three months later, the second questionnaire was sent to the students <italic>via</italic> email. The time period of 3 months was chosen because the study participants should not remember the questions of the first test when taking the second test, otherwise the result would be biased. A total of 25 people participated in both surveys.</p>
</sec>
</sec>
<sec id="S3.SS1.SSS2">
<title>Analysis</title>
<p>All analyses were conducted using IBM SPSS 27 and Excel. To determine convergent and discriminant validity, the Pearson correlation between the NIS and the four ES items was calculated. To evaluate convergent validity, the Pearson correlation between the NIS and <xref ref-type="bibr" rid="B67">Rotgans (2015)</xref> IIQ scale was calculated. In addition, to test convergent validity, the Average Variance Extracted (AVE) was calculated according to <xref ref-type="bibr" rid="B24">Fornell and Larcker (1981)</xref>:</p>
<disp-formula id="S3.Ex1"><mml:math id="M1" display="block"><mml:mrow><mml:mrow><mml:mi>A</mml:mi><mml:mi>V</mml:mi><mml:mpadded width="+5.6pt"><mml:mi>E</mml:mi></mml:mpadded></mml:mrow><mml:mo rspace="5.3pt">=</mml:mo><mml:mfrac><mml:mrow><mml:msubsup><mml:mo>&#x2211;</mml:mo><mml:mrow><mml:mpadded width="+2.8pt"><mml:mi>i</mml:mi></mml:mpadded><mml:mo>=</mml:mo><mml:mn>1</mml:mn></mml:mrow><mml:mi>p</mml:mi></mml:msubsup><mml:msubsup><mml:mi mathvariant="normal">&#x03BB;</mml:mi><mml:mi>i</mml:mi><mml:mn>2</mml:mn></mml:msubsup></mml:mrow><mml:mrow><mml:mrow><mml:msubsup><mml:mo>&#x2211;</mml:mo><mml:mrow><mml:mpadded width="+2.8pt"><mml:mi>i</mml:mi></mml:mpadded><mml:mo>=</mml:mo><mml:mn>1</mml:mn></mml:mrow><mml:mi>p</mml:mi></mml:msubsup><mml:msubsup><mml:mi mathvariant="normal">&#x03BB;</mml:mi><mml:mi>i</mml:mi><mml:mn>2</mml:mn></mml:msubsup></mml:mrow><mml:mo rspace="5.3pt">+</mml:mo><mml:mrow><mml:msubsup><mml:mo>&#x2211;</mml:mo><mml:mrow><mml:mpadded width="+2.8pt"><mml:mi>i</mml:mi></mml:mpadded><mml:mo>=</mml:mo><mml:mn>1</mml:mn></mml:mrow><mml:mi>p</mml:mi></mml:msubsup><mml:mrow><mml:mi>V</mml:mi><mml:mi>a</mml:mi><mml:mi>r</mml:mi><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:msub><mml:mi mathvariant="normal">&#x03B5;</mml:mi><mml:mi>i</mml:mi></mml:msub><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mrow></mml:mrow></mml:mrow></mml:mfrac></mml:mrow></mml:math></disp-formula>
<p>To test the three subscales of the interest scale for reliability and initial consistency, in addition to the Cronbach&#x2019;s Alpha, the composite reliability (CR) according to <xref ref-type="bibr" rid="B24">Fornell and Larcker (1981)</xref> was calculated:</p>
<disp-formula id="S3.Ex2"><mml:math id="M2" display="block"><mml:mrow><mml:mrow><mml:mi>C</mml:mi><mml:mpadded width="+5.6pt"><mml:mi>R</mml:mi></mml:mpadded></mml:mrow><mml:mo rspace="5.3pt">=</mml:mo><mml:mfrac><mml:msup><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:msubsup><mml:mo>&#x2211;</mml:mo><mml:mrow><mml:mpadded width="+2.8pt"><mml:mi>i</mml:mi></mml:mpadded><mml:mo>=</mml:mo><mml:mn>1</mml:mn></mml:mrow><mml:mi>p</mml:mi></mml:msubsup><mml:msub><mml:mi mathvariant="normal">&#x03BB;</mml:mi><mml:mi>i</mml:mi></mml:msub></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mn>2</mml:mn></mml:msup><mml:mrow><mml:msup><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:msubsup><mml:mo>&#x2211;</mml:mo><mml:mrow><mml:mpadded width="+2.8pt"><mml:mi>i</mml:mi></mml:mpadded><mml:mo>=</mml:mo><mml:mn>1</mml:mn></mml:mrow><mml:mi>p</mml:mi></mml:msubsup><mml:msub><mml:mi mathvariant="normal">&#x03BB;</mml:mi><mml:mi>i</mml:mi></mml:msub></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mn>2</mml:mn></mml:msup><mml:mo>+</mml:mo><mml:mrow><mml:msubsup><mml:mo>&#x2211;</mml:mo><mml:mrow><mml:mpadded width="+2.8pt"><mml:mi>i</mml:mi></mml:mpadded><mml:mo>=</mml:mo><mml:mn>1</mml:mn></mml:mrow><mml:mi>p</mml:mi></mml:msubsup><mml:mrow><mml:mi>V</mml:mi><mml:mi>a</mml:mi><mml:mi>r</mml:mi><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:msub><mml:mi mathvariant="normal">&#x03B5;</mml:mi><mml:mi>i</mml:mi></mml:msub><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mrow></mml:mrow></mml:mrow></mml:mfrac></mml:mrow></mml:math></disp-formula>
<p>To test the test-retest reliability, the Pearson correlation between the two test time points was calculated (<xref ref-type="bibr" rid="B79">Vilagut, 2014</xref>).</p>
</sec>
</sec>
<sec id="S3.SS2">
<title>Results</title>
<p>The correlations between <xref ref-type="bibr" rid="B67">Rotgans (2015)</xref> IIQ scale and the three components of the NIS are high (<italic>r</italic><sub>QII&#x2013;EMO</sub> = 0.836; <italic>r</italic><sub>QII &#x2013;COG</sub> = 0.723; <italic>r</italic><sub>QII &#x2013;VALUE</sub> = 0.720). The correlation between the ecosystem services and the three dimensions of interest scale are small (<italic>r</italic><sub>ES&#x2013;EMO</sub> = 0.173; <italic>r</italic><sub>ES&#x2013;COG</sub> = 0.136; <italic>r</italic><sub>ES&#x2013;VALUE</sub> = 0.198). AVE, CR, and Cronbach&#x2019;s alpha for the three interest subscales are shown in <xref ref-type="table" rid="T4">Table 4</xref>. The correlation between the two test time periods was <italic>r</italic> = 0.711 for the emotional component, <italic>r</italic> = 0.700 for the cognitive component, and <italic>r</italic> = 0.900 for the value-related component. All correlations were significant (<italic>p</italic> &#x003C; 0.05).</p>
<table-wrap position="float" id="T4">
<label>TABLE 4</label>
<caption><p>AVE, CF, and Cronbach&#x2019;s alpha for the three subscales of the interest scale.</p></caption>
<table cellspacing="5" cellpadding="5" frame="hsides" rules="groups">
<thead>
<tr>
<td valign="top" align="left"></td>
<td valign="top" align="center"><bold>EMO</bold></td>
<td valign="top" align="center"><bold>COG</bold></td>
<td valign="top" align="center"><bold>VALUE</bold></td>
</tr>
</thead>
<tbody>
<tr>
<td valign="top" align="left">AVE</td>
<td valign="top" align="center">0.542</td>
<td valign="top" align="center">0.558</td>
<td valign="top" align="center">0.635</td>
</tr>
<tr>
<td valign="top" align="left">CF</td>
<td valign="top" align="center">0.773</td>
<td valign="top" align="center">0.788</td>
<td valign="top" align="center">0.839</td>
</tr>
<tr>
<td valign="top" align="left">Cronbach&#x2019;s alpha</td>
<td valign="top" align="center">0.792</td>
<td valign="top" align="center">0.737</td>
<td valign="top" align="center">0.840</td>
</tr>
</tbody>
</table>
</table-wrap>
</sec>
<sec id="S3.SS3">
<title>Discussion</title>
<p>In the first step, the validity of the new measurement instrument should be further examined. In addition to content validity, on which special focus was already placed in study 1 (<xref ref-type="table" rid="T1">Table 1</xref>), discriminant and convergent validity, which also belong to construct validity, are particularly important (<xref ref-type="bibr" rid="B26">Ginty, 2012</xref>).</p>
<p>An instrument is considered to have convergent validity if it has a high statistical correlation to other instruments that measure something similar. Discriminant validity, on the other hand, means that an instrument is unrelated to measurement instruments of other constructs (<xref ref-type="bibr" rid="B13">Campbell and Fiske, 1959</xref>). To test both types of validity the Pearson correlation can be used (<xref ref-type="bibr" rid="B49">Lehmann, 1988</xref>). For convergent validity, the correlation should be as high as possible so that it can be assumed that the two instruments measure the same construct (<xref ref-type="bibr" rid="B16">Chin and Yao, 2014</xref>). As a general guideline, the correlation for demonstrating convergent validity should be greater than <italic>r</italic> = 0.7 (<xref ref-type="bibr" rid="B14">Carlson and Herdman, 2012</xref>).</p>
<p>For all three factors a very high correlation (<italic>r</italic> &#x003E; 0.7) to the IIQ scale of <xref ref-type="bibr" rid="B67">Rotgans (2015)</xref> could be found. This indicates that the NIS and the IIQ are very similar and presumably measure the same underlying construct (individual interest). Additionally, to verify convergent validity, the AVE was calculated. To confirm the validity of a scale, the AVE should be &#x003C;0.5 (<xref ref-type="bibr" rid="B1">Ahmad et al., 2016</xref>). For all three subscales of the newly developed scale, the AVE is above this cutoff value. Therefore, the results confirm the presence of sufficient convergent validity.</p>
<p>For testing discriminant validity, there is no specific cut of value for correlation. However, the correlation should be significantly lower than for convergent validity (<xref ref-type="bibr" rid="B37">Hubley, 2014</xref>). All three levels of the interest scale show only a small correlation with the ES items. Because interest in nature and the ES ratings are distinct, unrelated constructs, the low correlation provides evidence of discriminant validity.</p>
<p>A common method to test the reliability and initial consistency of a scale is the calculation of the CR (<xref ref-type="bibr" rid="B28">Hatcher and O&#x2019;Rourke, 2013</xref>) and the Cronbach&#x2019;s alpha (<xref ref-type="bibr" rid="B23">Field, 2013</xref>). However, both indicators are very similar (<xref ref-type="bibr" rid="B59">Peterson and Kim, 2013</xref>). For the Cronbach&#x2019;s alpha, values above 0.7 should be achieved (<xref ref-type="bibr" rid="B78">Tavakol and Dennick, 2011</xref>), for the composite reliability at least values of 0.6 (<xref ref-type="bibr" rid="B1">Ahmad et al., 2016</xref>). The results of both reliability measures are in an acceptable range for all three subscales. The alpha scores obtained are similar to those of other scales in the environmental field (<xref ref-type="bibr" rid="B55">Mayer and Frantz, 2004</xref>; <xref ref-type="bibr" rid="B56">Nisbet et al., 2009</xref>). Thus, reliability, internal consistency, and inter item homogeneity can be confirmed for the three subscales of the instrument.</p>
<p>When examining the test-retest reliability, it was found that for all three subscales a sufficiently high correlation exists between the two test times to indicate an acceptable test-retest reliability (<xref ref-type="bibr" rid="B20">Domino and Domino, 2006</xref>). The value-related component is shown to be particularly stable. This could be explained by the fact that the appreciation and personal valuation of nature is rather constant and almost does not change over a short period of time. It can be assumed that with a shorter survey interval (e.g., 2 weeks between the two survey dates) the test-retest reliability would have been even higher (<xref ref-type="bibr" rid="B12">B&#x00FC;hner, 2011</xref>).</p>
</sec>
</sec>
<sec id="S4">
<title>Study 3</title>
<p>To test whether an instrument is also suitable for a different target group, a CFA should be used (<xref ref-type="bibr" rid="B17">Costello and Osborne, 2005</xref>). Since the instrument should also be used with, for example, students with learning disabilities, it should be tested on a group of special needs students in study 3 and the factor structure should be re-examined.</p>
<sec id="S4.SS1">
<title>Methods</title>
<sec id="S4.SS1.SSS1">
<title>Participants</title>
<p>A total of 214 students (53.74% male, 44.39% female, 1.87% no answer) at three different special needs schools were surveyed. These are schools for students with learning disabilities, for whom attendance at a regular school would not be possible. Before the study was conducted approval was obtained from the relevant school authority (Hessian Ministry of Education and Religious Affairs). As part of this approval process, the consent of the school administration and the school conference was also obtained. The legal guardians of the surveyed students were informed about the study and asked for their written consent. Both parents and study participants were informed of the voluntary nature of the study. The data were collected anonymously and used for research purposes only.</p>
<p>Before the study began, the students were explained how a Likert scale works using everyday examples. The individual questions were read out loud to the students and a moment was waited after each question to allow the students to answer the questions. This procedure served as a supportive measure so that students with learning limitations could participate in the survey.</p>
</sec>
<sec id="S4.SS1.SSS2">
<title>Analysis</title>
<p>As in study 1, a CFA was conducted to test the factor structure of the NIS for this group as well. A model was tested in which the three levels of the interest construct were represented (as in study 1 in model 2). Again, missing values were replaced by series means and maximum likelihood estimation was used as fitting function. CFI, TLI, SRMR, and RMSEA were selected as fit indices.</p>
<p>In the analysis of the data sets, questionnaires that showed straightlining were excluded. Straightlining refers to questionnaires in which the same answer option was selected for each question. It is conceivable, for example, that a respondent may want to express a very strong interest in nature. However, such ticking behavior can also be an expression of inattention or disinterest in the task. Since straightlining occurs particularly in younger participants (<xref ref-type="bibr" rid="B76">Schonlau and Toepoel, 2015</xref>), the conservative approach was chosen and these data sets (<italic>n</italic> = 9) were not included in the analysis.</p>
</sec>
</sec>
<sec id="S4.SS2">
<title>Results</title>
<p>The CFA with the data of the 205 special needs students shows a significant &#x03C7;<sup>2</sup> test for the performed model (<italic>p</italic> &#x003C; 0.001). The ratio of chi-square to degree of freedom was 2.998 (&#x03C7;<sup>2</sup> = 71.72; df = 24). The remaining fit indices were slightly lower than the scores obtained by the university students in from study 1, with a value of 0.932 for the CFI, 0.898 for the TLI, 0.0561 for the SRMR, and 0.099 for the RMSEA.</p>
</sec>
<sec id="S4.SS3">
<title>Discussion</title>
<p>The results of the CFA with the data of the special education students show a slightly worse model fit than the data of the university students. The CFI is still in the acceptable range, while the TLI is slightly below the desired cut off value of 0.90 (<xref ref-type="bibr" rid="B11">Browne and Cudeck, 1992</xref>). The SRMR is in the acceptable range of below 0.08 (<xref ref-type="bibr" rid="B36">Hu and Bentler, 1999</xref>) and the RMSEA slightly exceeds the desired value of 0.08 but is still below 0.10 (<xref ref-type="bibr" rid="B11">Browne and Cudeck, 1992</xref>; <xref ref-type="bibr" rid="B51">MacCallum et al., 1996</xref>; <xref ref-type="bibr" rid="B5">Awang, 2015</xref>). Since these are only indicative values and the values obtained are still within the tolerance range of some authors, it can be assumed that the model for special needs students, although not a perfect fit, still is within an acceptable range. One explanation for the slightly worse model fit could be that the young special education students do not perceive the different levels of interest as differentiated as adults. Therefore, the distinction between value-related, emotional, and cognitive interests might be less pronounced in this group. This would have the consequence that the distinction in three levels represented by the model would not be perceived as well by the special needs students as it is by adults. Nevertheless, some points speak for the usability of the scale also with special needs students. For example, the instrument is comparatively short, so that it can be completed in a relatively short time. In addition, the items are easy to understand and even students with cognitive limitations can easily comprehend what is meant by the individual items.</p>
</sec>
</sec>
<sec id="S5">
<title>Limitations</title>
<p>Despite the fact that the study was conducted with great care, some limitations of the research have to be considered. For example, in study 1 the scale was tested for the most part on a very homogeneous sample (university students). For future studies, it would therefore be desirable to test the scale on a more generalized group of people (e.g., other age groups or social milieus). When testing the test-retest reliability, a time period of 3 months between the two test time points was selected. It is possible that a change in interest may have occurred during this time. Interest is less stable than, for example, personal values (<xref ref-type="bibr" rid="B22">Feather, 1995</xref>). Nevertheless, it can be assumed that the basic interest in a topic has not changed fundamentally over a period of 3 months and thus the measurement is valid.</p>
</sec>
<sec sec-type="conclusion" id="S6">
<title>Conclusion and Implications</title>
<p>Because of the high influence and relevance of interest, the assessment of the interest construct is still an important approach for research. However, current research often uses instruments that have not been tested for their psychological quality or do not adequately cover the construct of interest (<xref ref-type="bibr" rid="B68">Rowland et al., 2019</xref>). For this reason, no validated instrument for measuring interest in nature has existed in environmental psychology and environmental education research until now. This research gap shall be addressed with the NIS.</p>
<p>The instrument developed and tested here on interest in nature shows sufficient model fit, validity, and reliability. Thus, it offers starting points for further research. For example, it can be used to investigate the relationship between interest in nature and other environmental variables such as nature connectedness or environmental attitudes. It would be particularly useful, to compare interest in nature among individuals of different age groups. For other variables in environmental psychology such as nature connectedness or environmental attitudes, age effects have in fact already been observed (<xref ref-type="bibr" rid="B82">Wiernik et al., 2013</xref>; <xref ref-type="bibr" rid="B38">Hughes et al., 2019</xref>).</p>
<p>The success of environmental education programs in relation to interest in nature can also be assessed with the new measurement tool. It is already common in the evaluation of environmental education programs, for example, to look at changes in attitude, knowledge, or behavior (<xref ref-type="bibr" rid="B9">Braun et al., 2018</xref>). Interest in nature as a possible factor would be a useful addition here.</p>
</sec>
<sec sec-type="data-availability" id="S7">
<title>Data Availability Statement</title>
<p>The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.</p>
</sec>
<sec id="S8">
<title>Ethics Statement</title>
<p>The studies involving human participants were reviewed and approved by the Ethics Committee of the Science Didactic Institutes and Departments (FB 13, 14, 15) of the Goethe University Frankfurt am Main. Written informed consent to participate in this study was provided by the participants&#x2019; legal guardian/next of kin.</p>
</sec>
<sec id="S9">
<title>Author Contributions</title>
<p>VW, PD, and MK: conceptualization, methodology, writing &#x2013; review and editing, and visualization. VW, MK, and LD: data collection. MK: validation, formal analysis, investigation, and writing &#x2013; original. PD: funding acquisition. VW and PD: supervision. All authors contributed to the article and approved the submitted version.</p>
</sec>
<sec sec-type="COI-statement" id="conf1">
<title>Conflict of Interest</title>
<p>The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.</p>
</sec>
<sec sec-type="disclaimer" id="pudiscl1">
<title>Publisher&#x2019;s Note</title>
<p>All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.</p>
</sec>
</body>
<back>
<sec sec-type="funding-information" id="S10">
<title>Funding</title>
<p>This study was partly supported by the Opel-Zoo Foundation Professorship in Zoo Biology from the &#x201C;von Opel Hessische Zoostiftung.&#x201D;</p>
</sec>
<ack>
<p>We would like to thank all the people who participated in our survey. Special thanks go to the three schools that supported us in the data collection: Johann-Hinrich-Wichern-Schule in Frankfurt, Schule an der Br&#x00FC;hlsbacher Warte in Wetzlar, and Albert-Schweitzer-Schule in Gie&#x00DF;en.</p>
</ack>
<ref-list>
<title>References</title>
<ref id="B1"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Ahmad</surname> <given-names>S.</given-names></name> <name><surname>Zulkurnain</surname> <given-names>N.</given-names></name> <name><surname>Khairushalimi</surname> <given-names>F.</given-names></name></person-group> (<year>2016</year>). <article-title>Assessing the validity and reliability of a measurement model in structural equation modeling (SEM).</article-title> <source><italic>J. Adv. Math. Comput. Sci.</italic></source> <volume>15</volume> <fpage>1</fpage>&#x2013;<lpage>8</lpage>. <pub-id pub-id-type="doi">10.9734/bjmcs/2016/25183</pub-id></citation></ref>
<ref id="B2"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Ahnesj&#x00F6;</surname> <given-names>J.</given-names></name> <name><surname>Danielsson</surname> <given-names>T.</given-names></name></person-group> (<year>2020</year>). <article-title>Organized recreational fishing in school, knowledge about nature and influence on outdoor recreation habits.</article-title> <source><italic>J. Outdoor Environ. Educ.</italic></source> <volume>23</volume> <fpage>261</fpage>&#x2013;<lpage>273</lpage>. <pub-id pub-id-type="doi">10.1007/s42322-020-00061-8</pub-id></citation></ref>
<ref id="B3"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Ainley</surname> <given-names>M.</given-names></name></person-group> (<year>2017</year>). &#x201C;<article-title>Interest: knowns, unknowns, and basic processes</article-title>,&#x201D; in <source><italic>The Science of Interest</italic></source>, <role>eds</role> <person-group person-group-type="editor"><name><surname>O&#x2019;Keefe</surname> <given-names>P. A.</given-names></name> <name><surname>Harackiewicz</surname> <given-names>J. M.</given-names></name></person-group> (<publisher-loc>New York, NY</publisher-loc>: <publisher-name>Springer International Publishing</publisher-name>), <fpage>3</fpage>&#x2013;<lpage>24</lpage>. <pub-id pub-id-type="doi">10.1007/978-3-319-55509-6_1</pub-id></citation></ref>
<ref id="B4"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Ainley</surname> <given-names>M.</given-names></name> <name><surname>Hidi</surname> <given-names>S.</given-names></name> <name><surname>Berndorff</surname> <given-names>D.</given-names></name></person-group> (<year>2002</year>). <article-title>Interest, learning, and the psychological processes that mediate their relationship.</article-title> <source><italic>J. Educ. Psychol.</italic></source> <volume>94</volume> <fpage>545</fpage>&#x2013;<lpage>561</lpage>. <pub-id pub-id-type="doi">10.1037/0022-0663.94.3.545</pub-id></citation></ref>
<ref id="B5"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Awang</surname> <given-names>Z.</given-names></name></person-group> (<year>2015</year>). <source><italic>SEM Made Simple: A Gentle Approach to Learning Structural Equation Modeling.</italic></source> <publisher-loc>Bandar Baru Bangi</publisher-loc>: <publisher-name>MPWS Rich Publication</publisher-name>.</citation></ref>
<ref id="B6"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Boateng</surname> <given-names>G. O.</given-names></name> <name><surname>Neilands</surname> <given-names>T. B.</given-names></name> <name><surname>Frongillo</surname> <given-names>E. A.</given-names></name> <name><surname>Melgar-Qui&#x00F1;onez</surname> <given-names>H. R.</given-names></name> <name><surname>Young</surname> <given-names>S. L.</given-names></name></person-group> (<year>2018</year>). <article-title>Best practices for developing and validating scales for health, social, and behavioral research: a primer.</article-title> <source><italic>Front. Public Health</italic></source> <volume>6</volume>:<fpage>149</fpage>. <pub-id pub-id-type="doi">10.3389/fpubh.2018.00149</pub-id> <pub-id pub-id-type="pmid">29942800</pub-id></citation></ref>
<ref id="B7"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>B&#x00F8;e</surname> <given-names>M. V.</given-names></name></person-group> (<year>2012</year>). <article-title>Science choices in Norwegian upper secondary school: what matters?</article-title> <source><italic>Sci. Educ.</italic></source> <volume>96</volume> <fpage>1</fpage>&#x2013;<lpage>20</lpage>. <pub-id pub-id-type="doi">10.1002/sce.20461</pub-id></citation></ref>
<ref id="B8"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>B&#x00F8;e</surname> <given-names>M. V.</given-names></name> <name><surname>Henriksen</surname> <given-names>E. K.</given-names></name></person-group> (<year>2013</year>). <article-title>Love it or leave it: Norwegian students&#x2019; motivations and expectations for postcompulsory physics.</article-title> <source><italic>Sci. Educ.</italic></source> <volume>97</volume> <fpage>550</fpage>&#x2013;<lpage>573</lpage>. <pub-id pub-id-type="doi">10.1002/sce.21068</pub-id></citation></ref>
<ref id="B9"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Braun</surname> <given-names>T.</given-names></name> <name><surname>Cottrell</surname> <given-names>R.</given-names></name> <name><surname>Dierkes</surname> <given-names>P.</given-names></name></person-group> (<year>2018</year>). <article-title>Fostering changes in attitude, knowledge and behavior: demographic variation in environmental education effects.</article-title> <source><italic>Environ. Educ. Res.</italic></source> <volume>24</volume> <fpage>899</fpage>&#x2013;<lpage>920</lpage>. <pub-id pub-id-type="doi">10.1080/13504622.2017.1343279</pub-id></citation></ref>
<ref id="B10"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Brown</surname> <given-names>T. A.</given-names></name></person-group> (<year>2015</year>). <source><italic>Confirmatory Factor Analysis for Applied Research Methodology in the Social Sciences</italic></source>, <edition>2nd Edn</edition>. <publisher-loc>New York, NY</publisher-loc>: <publisher-name>Guilford Press</publisher-name>.</citation></ref>
<ref id="B11"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Browne</surname> <given-names>M. W.</given-names></name> <name><surname>Cudeck</surname> <given-names>R.</given-names></name></person-group> (<year>1992</year>). <article-title>Alternative ways of assessing model fit.</article-title> <source><italic>Sociol. Methods Res.</italic></source> <volume>21</volume> <fpage>230</fpage>&#x2013;<lpage>258</lpage>. <pub-id pub-id-type="doi">10.1177/0049124192021002005</pub-id></citation></ref>
<ref id="B12"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>B&#x00FC;hner</surname> <given-names>M.</given-names></name></person-group> (<year>2011</year>). <source><italic>Einf&#x00FC;hrung in Die Test- Und Fragebogenkonstruktion (3., aktualisierte und erw. Aufl.).</italic></source> <publisher-loc>Munich</publisher-loc>: <publisher-name>Pearson Studium</publisher-name>.</citation></ref>
<ref id="B13"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Campbell</surname> <given-names>D. T.</given-names></name> <name><surname>Fiske</surname> <given-names>D. W.</given-names></name></person-group> (<year>1959</year>). <article-title>Convergent and discriminant validation by the multitrait-multimethod matrix.</article-title> <source><italic>Psychol. Bull.</italic></source> <volume>56</volume> <fpage>81</fpage>&#x2013;<lpage>105</lpage>. <pub-id pub-id-type="doi">10.1037/h0046016</pub-id></citation></ref>
<ref id="B14"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Carlson</surname> <given-names>K. D.</given-names></name> <name><surname>Herdman</surname> <given-names>A. O.</given-names></name></person-group> (<year>2012</year>). <article-title>Understanding the impact of convergent validity on research results.</article-title> <source><italic>Organ. Res. Methods</italic></source> <volume>15</volume> <fpage>17</fpage>&#x2013;<lpage>32</lpage>. <pub-id pub-id-type="doi">10.1177/1094428110392383</pub-id></citation></ref>
<ref id="B15"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Carpenter</surname> <given-names>S.</given-names></name></person-group> (<year>2018</year>). <article-title>Ten steps in scale development and reporting: a guide for researchers.</article-title> <source><italic>Commun. Methods Meas.</italic></source> <volume>12</volume> <fpage>25</fpage>&#x2013;<lpage>44</lpage>. <pub-id pub-id-type="doi">10.1080/19312458.2017.1396583</pub-id></citation></ref>
<ref id="B16"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Chin</surname> <given-names>C.-L.</given-names></name> <name><surname>Yao</surname> <given-names>G.</given-names></name></person-group> (<year>2014</year>). &#x201C;<article-title>Convergent validity</article-title>,&#x201D; in <source><italic>Encyclopedia of Quality of Life and Well-Being Research</italic></source>, <role>ed.</role> <person-group person-group-type="editor"><name><surname>Michalos</surname> <given-names>A. C.</given-names></name></person-group> (<publisher-loc>Berlin</publisher-loc>: <publisher-name>Springer</publisher-name>), <fpage>1275</fpage>&#x2013;<lpage>1276</lpage>. <pub-id pub-id-type="doi">10.1007/978-94-007-0753-5_573</pub-id> <pub-id pub-id-type="pmid">33250610</pub-id></citation></ref>
<ref id="B17"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Costello</surname> <given-names>A. B.</given-names></name> <name><surname>Osborne</surname> <given-names>J.</given-names></name></person-group> (<year>2005</year>). <article-title>Best practices in exploratory factor analysis: four recommendations for getting the most from your analysis.</article-title> <source><italic>Pract. Assess. Res. Eval.</italic></source> <volume>10</volume> <fpage>1</fpage>&#x2013;<lpage>9</lpage>. <pub-id pub-id-type="doi">10.7275/jyj1-4868</pub-id></citation></ref>
<ref id="B18"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Denissen</surname> <given-names>J. J. A.</given-names></name> <name><surname>Zarrett</surname> <given-names>N. R.</given-names></name> <name><surname>Eccles</surname> <given-names>J. S.</given-names></name></person-group> (<year>2007</year>). <article-title>I like to do it, I&#x2019;m able, and I know I am: longitudinal couplings between domain-specific achievement, self-concept, and interest.</article-title> <source><italic>Child Dev.</italic></source> <volume>78</volume> <fpage>430</fpage>&#x2013;<lpage>447</lpage>. <pub-id pub-id-type="doi">10.1111/j.1467-8624.2007.01007.x</pub-id> <pub-id pub-id-type="pmid">17381782</pub-id></citation></ref>
<ref id="B19"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Dewey</surname> <given-names>J.</given-names></name></person-group> (<year>1913</year>). <source><italic>Riverside Educational Monographs. Interest and Effort in Education.</italic></source> <publisher-loc>New York, NY</publisher-loc>: <publisher-name>Mifflin and Company</publisher-name>.</citation></ref>
<ref id="B20"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Domino</surname> <given-names>G.</given-names></name> <name><surname>Domino</surname> <given-names>M. L.</given-names></name></person-group> (<year>2006</year>). <source><italic>Psychological Testing: An Introduction</italic></source>, <edition>2nd Edn</edition>. <publisher-loc>Cambridge</publisher-loc>: <publisher-name>Cambridge University Press</publisher-name>.</citation></ref>
<ref id="B21"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Faul</surname> <given-names>F.</given-names></name> <name><surname>Erdfelder</surname> <given-names>E.</given-names></name> <name><surname>Buchner</surname> <given-names>A.</given-names></name> <name><surname>Lang</surname> <given-names>A.-G.</given-names></name></person-group> (<year>2009</year>). <article-title>Statistical power analyses using G<sup>&#x2217;</sup>Power 3.1: tests for correlation and regression analyses.</article-title> <source><italic>Behav. Res. Methods</italic></source> <volume>41</volume> <fpage>1149</fpage>&#x2013;<lpage>1160</lpage>. <pub-id pub-id-type="doi">10.3758/BRM.41.4.1149</pub-id> <pub-id pub-id-type="pmid">19897823</pub-id></citation></ref>
<ref id="B22"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Feather</surname> <given-names>N. T.</given-names></name></person-group> (<year>1995</year>). <article-title>Values, valences, and choice: the influences of values on the perceived attractiveness and choice of alternatives.</article-title> <source><italic>J. Pers. Soc. Psychol.</italic></source> <volume>68</volume> <fpage>1135</fpage>&#x2013;<lpage>1151</lpage>. <pub-id pub-id-type="doi">10.1037/0022-3514.68.6.1135</pub-id></citation></ref>
<ref id="B23"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Field</surname> <given-names>A.</given-names></name></person-group> (<year>2013</year>). <source><italic>Discovering Statistics Using IBM SPSS Statistics: And Sex and Drugs and Rock &#x2018;n&#x2019; roll</italic></source>, <edition>4th Edn</edition>. <publisher-loc>Thousand Oaks, CA</publisher-loc>: <publisher-name>Sage</publisher-name>.</citation></ref>
<ref id="B24"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Fornell</surname> <given-names>C.</given-names></name> <name><surname>Larcker</surname> <given-names>D. F.</given-names></name></person-group> (<year>1981</year>). <article-title>Evaluating structural equation models with unobservable variables and measurement error.</article-title> <source><italic>J. Market. Res.</italic></source> <volume>18</volume>:<fpage>39</fpage>. <pub-id pub-id-type="doi">10.2307/3151312</pub-id></citation></ref>
<ref id="B25"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Frey</surname> <given-names>A.</given-names></name> <name><surname>Taskinen</surname> <given-names>P.</given-names></name> <name><surname>Sch&#x00FC;tte</surname> <given-names>K.</given-names></name> <name><surname>Deutschland</surname> <given-names>P.-K.</given-names></name></person-group> (<year>2009</year>). <source><italic>PISA 2006 Skalenhandbuch: Dokumentation der Erhebungsinstrumente (1. Auflage).</italic></source> <publisher-loc>M&#x00FC;nster</publisher-loc>: <publisher-name>Waxmann Verlag GmbH</publisher-name>.</citation></ref>
<ref id="B26"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Ginty</surname> <given-names>A. T.</given-names></name></person-group> (<year>2012</year>). &#x201C;<article-title>Construct validity</article-title>,&#x201D; in <source><italic>Springer Reference. Encyclopedia of Behavioral Medicine</italic></source>, <role>ed.</role> <person-group person-group-type="editor"><name><surname>Gellman</surname> <given-names>M. D.</given-names></name></person-group> (<publisher-loc>Berlin</publisher-loc>: <publisher-name>Springer</publisher-name>), <fpage>487</fpage>.</citation></ref>
<ref id="B27"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Harackiewicz</surname> <given-names>J. M.</given-names></name> <name><surname>Barron</surname> <given-names>K. E.</given-names></name> <name><surname>Tauer</surname> <given-names>J. M.</given-names></name> <name><surname>Elliot</surname> <given-names>A. J.</given-names></name></person-group> (<year>2002</year>). <article-title>Predicting success in college: a longitudinal study of achievement goals and ability measures as predictors of interest and performance from freshman year through graduation.</article-title> <source><italic>J. Educ. Psychol.</italic></source> <volume>94</volume> <fpage>562</fpage>&#x2013;<lpage>575</lpage>. <pub-id pub-id-type="doi">10.1037/0022-0663.94.3.562</pub-id></citation></ref>
<ref id="B28"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Hatcher</surname> <given-names>P. D. L.</given-names></name> <name><surname>O&#x2019;Rourke</surname> <given-names>R. D. P. N.</given-names></name></person-group> (<year>2013</year>). <source><italic>Step-by-Step Approach to Using SAS for Factor Analysis and Structural Equation Modeling.</italic></source> <publisher-loc>Cary, NC</publisher-loc>: <publisher-name>SAS Institute</publisher-name>.</citation></ref>
<ref id="B29"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Hidi</surname> <given-names>S.</given-names></name> <name><surname>Renninger</surname> <given-names>K. A.</given-names></name> <name><surname>Krapp</surname> <given-names>A.</given-names></name></person-group> (<year>2004</year>). &#x201C;<article-title>Interest, a motivational variable that combines affective and cognitive functioning</article-title>,&#x201D; in <source><italic>The Educational Psychology Series. Motivation, Emotion, and Cognition: Integrative Perspectives on Intellectual Functioning and Development</italic></source>, <role>eds</role> <person-group person-group-type="editor"><name><surname>Dai</surname> <given-names>D. Y.</given-names></name> <name><surname>Sternberg</surname> <given-names>R. J.</given-names></name></person-group> (<publisher-loc>Mahwah, NJ</publisher-loc>: <publisher-name>Lawrence Erlbaum Associates Publishers</publisher-name>), <fpage>89</fpage>&#x2013;<lpage>115</lpage>.</citation></ref>
<ref id="B30"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Hidi</surname> <given-names>S.</given-names></name></person-group> (<year>1990</year>). <article-title>Interest and its contribution as a mental resource for learning.</article-title> <source><italic>Rev. Educ. Res.</italic></source> <volume>60</volume> <fpage>549</fpage>&#x2013;<lpage>571</lpage>. <pub-id pub-id-type="doi">10.3102/00346543060004549</pub-id></citation></ref>
<ref id="B31"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Hidi</surname> <given-names>S.</given-names></name></person-group> (<year>2006</year>). <article-title>Interest: a unique motivational variable.</article-title> <source><italic>Educ. Res. Rev.</italic></source> <volume>1</volume> <fpage>69</fpage>&#x2013;<lpage>82</lpage>. <pub-id pub-id-type="doi">10.1016/j.edurev.2006.09.001</pub-id></citation></ref>
<ref id="B32"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Hidi</surname> <given-names>S.</given-names></name> <name><surname>Anderson</surname> <given-names>V.</given-names></name></person-group> (<year>1992</year>). &#x201C;<article-title>Situational interest and its impact on reading and expository writing</article-title>,&#x201D; in <source><italic>The Role of Interest in Learning and Development</italic></source>, <role>eds</role> <person-group person-group-type="editor"><name><surname>Renninger</surname> <given-names>K. A.</given-names></name> <name><surname>Hidi</surname> <given-names>S.</given-names></name> <name><surname>Krapp</surname> <given-names>A.</given-names></name></person-group> (<publisher-loc>Mahwah, NJ</publisher-loc>: <publisher-name>Lawrence Erlbaum Associates Publishers</publisher-name>).</citation></ref>
<ref id="B33"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Hidi</surname> <given-names>S.</given-names></name> <name><surname>Renninger</surname> <given-names>K. A.</given-names></name></person-group> (<year>2006</year>). <article-title>The four-phase model of interest development.</article-title> <source><italic>Educ. Psychol.</italic></source> <volume>41</volume> <fpage>111</fpage>&#x2013;<lpage>127</lpage>. <pub-id pub-id-type="doi">10.1207/s15326985ep4102_4</pub-id></citation></ref>
<ref id="B34"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Holstermann</surname> <given-names>N.</given-names></name></person-group> (<year>2009</year>). <source><italic>Interesse Von Sch&#x00FC;lerinnen und Sch&#x00FC;lern an Biologischen Themen: Zur Bedeutung Von Hands-on Erfahrungen und Emotionalem Erleben.</italic></source> <comment>Ph.D. thesis</comment>. <publisher-loc>G&#x00F6;ttingen</publisher-loc>: <publisher-name>Georg-August-University</publisher-name>.</citation></ref>
<ref id="B35"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Holstermann</surname> <given-names>N.</given-names></name> <name><surname>Ainley</surname> <given-names>M.</given-names></name> <name><surname>Grube</surname> <given-names>D.</given-names></name> <name><surname>Roick</surname> <given-names>T.</given-names></name> <name><surname>B&#x00F6;geholz</surname> <given-names>S.</given-names></name></person-group> (<year>2012</year>). <article-title>The specific relationship between disgust and interest: relevance during biology class dissections and gender differences.</article-title> <source><italic>Learn. Instr.</italic></source> <volume>22</volume> <fpage>185</fpage>&#x2013;<lpage>192</lpage>. <pub-id pub-id-type="doi">10.1016/j.learninstruc.2011.10.005</pub-id></citation></ref>
<ref id="B36"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Hu</surname> <given-names>L. T.</given-names></name> <name><surname>Bentler</surname> <given-names>P. M.</given-names></name></person-group> (<year>1999</year>). <article-title>Cutoff criteria for fit indexes in covariance structure analysis: conventional criteria versus new alternatives.</article-title> <source><italic>Struct. Equ. Model.</italic></source> <volume>6</volume> <fpage>1</fpage>&#x2013;<lpage>55</lpage>. <pub-id pub-id-type="doi">10.1080/10705519909540118</pub-id></citation></ref>
<ref id="B37"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Hubley</surname> <given-names>A. M.</given-names></name></person-group> (<year>2014</year>). &#x201C;<article-title>Discriminant validity</article-title>,&#x201D; in <source><italic>Encyclopedia of Quality of Life and Well-Being Research</italic></source>, <role>ed.</role> <person-group person-group-type="editor"><name><surname>Michalos</surname> <given-names>A. C.</given-names></name></person-group> (<publisher-loc>Berlin</publisher-loc>: <publisher-name>Springer</publisher-name>), <fpage>1664</fpage>&#x2013;<lpage>1667</lpage>. <pub-id pub-id-type="doi">10.1007/978-94-007-0753-5_751</pub-id></citation></ref>
<ref id="B38"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Hughes</surname> <given-names>J.</given-names></name> <name><surname>Rogerson</surname> <given-names>M.</given-names></name> <name><surname>Barton</surname> <given-names>J.</given-names></name> <name><surname>Bragg</surname> <given-names>R.</given-names></name></person-group> (<year>2019</year>). <article-title>Age and connection to nature: when is engagement critical?</article-title> <source><italic>Front. Ecol. Environ.</italic></source> <volume>17</volume>:<fpage>265</fpage>&#x2013;<lpage>269</lpage>. <pub-id pub-id-type="doi">10.1002/fee.2035</pub-id></citation></ref>
<ref id="B39"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Kleespies</surname> <given-names>M. W.</given-names></name> <name><surname>Montes</surname> <given-names>N. &#x00C1;</given-names></name> <name><surname>Bambach</surname> <given-names>A. M.</given-names></name> <name><surname>Gricar</surname> <given-names>E.</given-names></name> <name><surname>Wenzel</surname> <given-names>V.</given-names></name> <name><surname>Dierkes</surname> <given-names>P. W.</given-names></name></person-group> (<year>2021</year>). <article-title>Identifying factors influencing attitudes towards species conservation&#x2013;a transnational study in the context of zoos.</article-title> <source><italic>Environ. Educ. Res.</italic></source> <volume>27</volume> <fpage>1421</fpage>&#x2013;<lpage>1439</lpage>. <pub-id pub-id-type="doi">10.1080/13504622.2021.1927993</pub-id></citation></ref>
<ref id="B40"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>K&#x00F6;ller</surname> <given-names>O.</given-names></name> <name><surname>Baumert</surname> <given-names>J.</given-names></name> <name><surname>Schnabel</surname> <given-names>K.</given-names></name></person-group> (<year>2001</year>). <article-title>Does interest matter? The relationship between academic interest and achievement in mathematics.</article-title> <source><italic>J. Res. Math. Educ.</italic></source> <volume>32</volume>:<fpage>448</fpage>. <pub-id pub-id-type="doi">10.2307/749801</pub-id></citation></ref>
<ref id="B41"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>K&#x00F6;ller</surname> <given-names>O.</given-names></name> <name><surname>Daniels</surname> <given-names>Z.</given-names></name> <name><surname>Schnabel</surname> <given-names>K. U.</given-names></name> <name><surname>Baumert</surname> <given-names>J.</given-names></name></person-group> (<year>2000</year>). <article-title>Kurswahlen von M&#x00E4;dchen und Jungen im Fach Mathematik: zur rolle von fachspezifischem Selbstkonzept und interesse.</article-title> <source><italic>Z. P&#x00E4;dagogische Psychol.</italic></source> <volume>14</volume> <fpage>26</fpage>&#x2013;<lpage>37</lpage>. <pub-id pub-id-type="doi">10.1024//1010-0652.14.1.26</pub-id></citation></ref>
<ref id="B42"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Krapp</surname> <given-names>A.</given-names></name></person-group> (<year>1998</year>). <article-title>Entwicklung und F&#x00F6;rderung von interessen im unterricht.</article-title> <source><italic>Psychol.Erzieh. Unterr.</italic></source> <volume>45</volume> <fpage>186</fpage>&#x2013;<lpage>203</lpage>.</citation></ref>
<ref id="B43"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Krapp</surname> <given-names>A.</given-names></name></person-group> (<year>1992</year>). <article-title>Interesse, Lernen und Leistung. Neue Forschungsans&#x00E4;tze in der P&#x00E4;dagogischen psychologie.</article-title> <source><italic>Z. P&#x00E4;d.</italic></source> <volume>5</volume> <fpage>747</fpage>&#x2013;<lpage>770</lpage>.</citation></ref>
<ref id="B44"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Krapp</surname> <given-names>A.</given-names></name></person-group> (<year>1993</year>). <article-title>The construct of interest: characteristics of indvidual interests and interest-related actions from the perspective of a person-object-theory.</article-title> <source><italic>Stud. Educ. Psychol.</italic></source> <volume>4</volume> <fpage>1</fpage>&#x2013;<lpage>18</lpage>.</citation></ref>
<ref id="B45"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Krapp</surname> <given-names>A.</given-names></name></person-group> (<year>1999</year>). <article-title>Interest, motivation and learning: an educational-psychological perspective.</article-title> <source><italic>Eur. J. Psychol. Educ.</italic></source> <volume>14</volume> <fpage>23</fpage>&#x2013;<lpage>40</lpage>. <pub-id pub-id-type="doi">10.1007/BF03173109</pub-id></citation></ref>
<ref id="B46"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Krapp</surname> <given-names>A.</given-names></name></person-group> (<year>2000</year>). &#x201C;<article-title>Interest and Human development during adolescence: an educational-psychological approach</article-title>,&#x201D; in <source><italic>Advances in Psychology. Motivational psychology of Human Development: Developing Motivation and Motivating Development</italic></source>, <volume>Vol. 131</volume> <role>ed.</role> <person-group person-group-type="editor"><name><surname>Heckhausen</surname> <given-names>J.</given-names></name></person-group> (<publisher-loc>North-Holland</publisher-loc>: <publisher-name>Elsevier</publisher-name>), <fpage>109</fpage>&#x2013;<lpage>128</lpage>. <pub-id pub-id-type="doi">10.1016/S0166-4115(00)80008-4</pub-id></citation></ref>
<ref id="B47"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Krapp</surname> <given-names>A.</given-names></name></person-group> (<year>2002</year>). &#x201C;<article-title>An educational-psychological theory of interest and its relation to SDT</article-title>,&#x201D; in <source><italic>Handbook of Self-Determination Research</italic></source>, <role>eds</role> <person-group person-group-type="editor"><name><surname>Deci</surname> <given-names>E. L.</given-names></name> <name><surname>Ryan</surname> <given-names>R. M.</given-names></name></person-group> (<publisher-loc>Rochester, NY</publisher-loc>: <publisher-name>University of Rochester Press</publisher-name>). <pub-id pub-id-type="doi">10.18821/0869-2084-2018-63-5-267-272</pub-id> <pub-id pub-id-type="pmid">30689318</pub-id></citation></ref>
<ref id="B48"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Krapp</surname> <given-names>A.</given-names></name> <name><surname>Prenzel</surname> <given-names>M.</given-names></name></person-group> (<year>2011</year>). <article-title>Research on interest in science: theories, methods, and findings.</article-title> <source><italic>Int. J. Sci. Educ.</italic></source> <volume>33</volume> <fpage>27</fpage>&#x2013;<lpage>50</lpage>. <pub-id pub-id-type="doi">10.1080/09500693.2010.518645</pub-id></citation></ref>
<ref id="B49"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Lehmann</surname> <given-names>D. R.</given-names></name></person-group> (<year>1988</year>). <article-title>An alternative procedure for assessing convergent and discriminant validity.</article-title> <source><italic>Appl. Psychol. Meas.</italic></source> <volume>12</volume> <fpage>411</fpage>&#x2013;<lpage>423</lpage>. <pub-id pub-id-type="doi">10.1177/014662168801200409</pub-id></citation></ref>
<ref id="B50"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Linnenbrink-Garcia</surname> <given-names>L.</given-names></name> <name><surname>Durik</surname> <given-names>A. M.</given-names></name> <name><surname>Conley</surname> <given-names>A. M.</given-names></name> <name><surname>Barron</surname> <given-names>K. E.</given-names></name> <name><surname>Tauer</surname> <given-names>J. M.</given-names></name> <name><surname>Karabenick</surname> <given-names>S. A.</given-names></name><etal/></person-group> (<year>2010</year>). <article-title>Measuring situational interest in academic domains.</article-title> <source><italic>Educ. Psychol. Meas.</italic></source> <volume>70</volume> <fpage>647</fpage>&#x2013;<lpage>671</lpage>. <pub-id pub-id-type="doi">10.1177/0013164409355699</pub-id></citation></ref>
<ref id="B51"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>MacCallum</surname> <given-names>R. C.</given-names></name> <name><surname>Browne</surname> <given-names>M. W.</given-names></name> <name><surname>Sugawara</surname> <given-names>H. M.</given-names></name></person-group> (<year>1996</year>). <article-title>Power analysis and determination of sample size for covariance structure modeling.</article-title> <source><italic>Psychol. Methods</italic></source> <volume>1</volume> <fpage>130</fpage>&#x2013;<lpage>149</lpage>. <pub-id pub-id-type="doi">10.1037/1082-989X.1.2.130</pub-id></citation></ref>
<ref id="B52"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Mang</surname> <given-names>J.</given-names></name> <name><surname>Ustjanzew</surname> <given-names>N.</given-names></name> <name><surname>Le&#x00DF;ke</surname> <given-names>I.</given-names></name> <name><surname>Schiepe-Tiska</surname> <given-names>A.</given-names></name> <name><surname>Reiss</surname> <given-names>K.</given-names></name></person-group> (<year>2019</year>). <source><italic>PISA 2015 Skalenhandbuch: Dokumentation der Erhebungsinstrumente.</italic></source> <publisher-loc>M&#x00FC;nster</publisher-loc>: <publisher-name>Waxmann</publisher-name>.</citation></ref>
<ref id="B53"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Mang</surname> <given-names>J.</given-names></name> <name><surname>Ustjanzew</surname> <given-names>N.</given-names></name> <name><surname>Schiepe-Tiska</surname> <given-names>A.</given-names></name> <name><surname>Prenzel</surname> <given-names>M.</given-names></name> <name><surname>S&#x00E4;lzer</surname> <given-names>C.</given-names></name> <name><surname>M&#x00FC;ller</surname> <given-names>K.</given-names></name><etal/></person-group> (<year>2018</year>). <source><italic>PISA 2012 Skalenhandbuch: Dokumentation der Erhebungsinstrumente.</italic></source> <publisher-loc>M&#x00FC;nster</publisher-loc>: <publisher-name>Waxmann</publisher-name>.</citation></ref>
<ref id="B54"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Marsh</surname> <given-names>H. W.</given-names></name> <name><surname>Balla</surname> <given-names>J. R.</given-names></name> <name><surname>McDonald</surname> <given-names>R. P.</given-names></name></person-group> (<year>1988</year>). <article-title>Goodness-of-fit indexes in confirmatory factor analysis: the effect of sample size.</article-title> <source><italic>Psychol. Bull.</italic></source> <volume>103</volume> <fpage>391</fpage>&#x2013;<lpage>410</lpage>. <pub-id pub-id-type="doi">10.1037/0033-2909.103.3.391</pub-id></citation></ref>
<ref id="B55"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Mayer</surname> <given-names>F. S.</given-names></name> <name><surname>Frantz</surname> <given-names>C. M.</given-names></name></person-group> (<year>2004</year>). <article-title>The connectedness to nature scale: a measure of individuals&#x2019; feeling in community with nature.</article-title> <source><italic>J. Environ. Psychol.</italic></source> <volume>24</volume> <fpage>503</fpage>&#x2013;<lpage>515</lpage>. <pub-id pub-id-type="doi">10.1016/j.jenvp.2004.10.001</pub-id></citation></ref>
<ref id="B56"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Nisbet</surname> <given-names>E. K.</given-names></name> <name><surname>Zelenski</surname> <given-names>J. M.</given-names></name> <name><surname>Murphy</surname> <given-names>S. A.</given-names></name></person-group> (<year>2009</year>). <article-title>The nature relatedness scale: linking individuals&#x2019; connection with nature to environmental concern and behavior.</article-title> <source><italic>Environ. Behav.</italic></source> <volume>41</volume> <fpage>715</fpage>&#x2013;<lpage>740</lpage>. <pub-id pub-id-type="doi">10.1177/0013916508318748</pub-id></citation></ref>
<ref id="B57"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Palmberg</surname> <given-names>I.</given-names></name> <name><surname>K&#x00E4;rkk&#x00E4;inen</surname> <given-names>S.</given-names></name> <name><surname>Jeronen</surname> <given-names>E.</given-names></name> <name><surname>Yli-Panula</surname> <given-names>E.</given-names></name> <name><surname>Persson</surname> <given-names>C.</given-names></name></person-group> (<year>2019</year>). <article-title>Nordic student teachers&#x2019; views on the most efficient teaching and learning methods for species and species identification.</article-title> <source><italic>Sustainability</italic></source> <volume>11</volume>:<fpage>5231</fpage>. <pub-id pub-id-type="doi">10.3390/su11195231</pub-id></citation></ref>
<ref id="B58"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Pawek</surname> <given-names>C.</given-names></name></person-group> (<year>2009</year>). <source><italic>Sch&#x00FC;lerlabore als Interessef&#x00F6;rdernde Au&#x00DF;erschulische Lernumgebungen f&#x00FC;r Sch&#x00FC;lerinnen und Sch&#x00FC;ler aus der Mittel- und Oberstufe.</italic></source> <comment>Ph.D. thesis.</comment> <publisher-loc>Kiel</publisher-loc>: <publisher-name>Christian-Albrecht University</publisher-name>.</citation></ref>
<ref id="B59"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Peterson</surname> <given-names>R. A.</given-names></name> <name><surname>Kim</surname> <given-names>Y.</given-names></name></person-group> (<year>2013</year>). <article-title>On the relationship between coefficient alpha and composite reliability.</article-title> <source><italic>J. Appl. Psychol.</italic></source> <volume>98</volume> <fpage>194</fpage>&#x2013;<lpage>198</lpage>. <pub-id pub-id-type="doi">10.1037/a0030767</pub-id> <pub-id pub-id-type="pmid">23127213</pub-id></citation></ref>
<ref id="B60"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Prenzel</surname> <given-names>M.</given-names></name></person-group> (<year>1992</year>). &#x201C;<article-title>The selective persistence of interest</article-title>,&#x201D; in <source><italic>The Role of Interest in Learning and Development</italic></source>, <role>eds</role> <person-group person-group-type="editor"><name><surname>Renninger</surname> <given-names>K. A.</given-names></name> <name><surname>Hidi</surname> <given-names>S.</given-names></name> <name><surname>Krapp</surname> <given-names>A.</given-names></name></person-group> (<publisher-loc>Mahwah, NJ</publisher-loc>: <publisher-name>Lawrence Erlbaum Associates, Inc</publisher-name>), <fpage>71</fpage>&#x2013;<lpage>98</lpage>.</citation></ref>
<ref id="B61"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Prenzel</surname> <given-names>M.</given-names></name> <name><surname>Krapp</surname> <given-names>A.</given-names></name> <name><surname>Schiefele</surname> <given-names>U.</given-names></name></person-group> (<year>1986</year>). <article-title>Grundz&#x00FC;ge einer p&#x00E4;dagogischen interessentheorie.</article-title> <source><italic>Z. P&#x00E4;d.</italic></source> <volume>32</volume> <fpage>163</fpage>&#x2013;<lpage>173</lpage>.</citation></ref>
<ref id="B62"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Raubenheimer</surname> <given-names>J.</given-names></name></person-group> (<year>2004</year>). <article-title>An item selection procedure to maximise scale reliability and validity.</article-title> <source><italic>SA J. Ind. Psychol.</italic></source> <volume>30</volume> <fpage>59</fpage>&#x2013;<lpage>64</lpage>. <pub-id pub-id-type="doi">10.4102/sajip.v30i4.168</pub-id></citation></ref>
<ref id="B63"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Renninger</surname> <given-names>K. A.</given-names></name> <name><surname>Hidi</surname> <given-names>S.</given-names></name></person-group> (<year>2002</year>). &#x201C;<article-title>Student interest and achievement: developmental issues raised by a case study</article-title>,&#x201D; in <source><italic>Educational Psychology Series. Development of Achievement Motivation</italic></source>, <role>eds</role> <person-group person-group-type="editor"><name><surname>Wigfield</surname> <given-names>A.</given-names></name> <name><surname>Eccles</surname> <given-names>J.</given-names></name></person-group> (<publisher-loc>Cambridge, MA</publisher-loc>: <publisher-name>Academic Press</publisher-name>), <fpage>173</fpage>&#x2013;<lpage>195</lpage>. <pub-id pub-id-type="doi">10.1016/B978-012750053-9/50009-7</pub-id></citation></ref>
<ref id="B64"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Renninger</surname> <given-names>K. A.</given-names></name> <name><surname>Hidi</surname> <given-names>S.</given-names></name></person-group> (<year>2011</year>). <article-title>Revisiting the conceptualization, measurement, and generation of interest.</article-title> <source><italic>Educ. Psychol.</italic></source> <volume>46</volume> <fpage>168</fpage>&#x2013;<lpage>184</lpage>. <pub-id pub-id-type="doi">10.1080/00461520.2011.587723</pub-id></citation></ref>
<ref id="B65"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Renninger</surname> <given-names>K. A.</given-names></name> <name><surname>Ewen</surname> <given-names>L.</given-names></name> <name><surname>Lasher</surname> <given-names>A. K.</given-names></name></person-group> (<year>2002</year>). <article-title>Individual interest as context in expository text and mathematical word problems.</article-title> <source><italic>Learn. Instr.</italic></source> <volume>12</volume> <fpage>467</fpage>&#x2013;<lpage>490</lpage>. <pub-id pub-id-type="doi">10.1016/S0959-4752(01)00012-3</pub-id></citation></ref>
<ref id="B66"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Romine</surname> <given-names>W.</given-names></name> <name><surname>Sadler</surname> <given-names>T. D.</given-names></name> <name><surname>Presley</surname> <given-names>M.</given-names></name> <name><surname>Klosterman</surname> <given-names>M. L.</given-names></name></person-group> (<year>2014</year>). <article-title>Student interest in technology and science (SITS) survey: development, validation, and use of a new instrument.</article-title> <source><italic>Int. J. Sci. Math. Educ.</italic></source> <volume>12</volume> <fpage>261</fpage>&#x2013;<lpage>283</lpage>. <pub-id pub-id-type="doi">10.1007/s10763-013-9410-3</pub-id></citation></ref>
<ref id="B67"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Rotgans</surname> <given-names>J. I.</given-names></name></person-group> (<year>2015</year>). <article-title>Validation study of a general subject-matter interest measure: the individual interest questionnaire (IIQ).</article-title> <source><italic>Health Prof. Educ.</italic></source> <volume>1</volume> <fpage>67</fpage>&#x2013;<lpage>75</lpage>. <pub-id pub-id-type="doi">10.1016/j.hpe.2015.11.009</pub-id></citation></ref>
<ref id="B68"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Rowland</surname> <given-names>A. A.</given-names></name> <name><surname>Knekta</surname> <given-names>E.</given-names></name> <name><surname>Eddy</surname> <given-names>S.</given-names></name> <name><surname>Corwin</surname> <given-names>L. A.</given-names></name></person-group> (<year>2019</year>). <article-title>Defining and measuring students&#x2019; interest in biology: an analysis of the biology education literature.</article-title> <source><italic>CBE Life Sci. Educ.</italic></source> <volume>18</volume>:<fpage>ar34</fpage>. <pub-id pub-id-type="doi">10.1187/cbe.19-02-0037</pub-id> <pub-id pub-id-type="pmid">31397650</pub-id></citation></ref>
<ref id="B69"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Rusticus</surname> <given-names>S.</given-names></name></person-group> (<year>2014</year>). &#x201C;<article-title>Content validity</article-title>,&#x201D; in <source><italic>Encyclopedia of Quality of Life and Well-Being Research</italic></source>, <role>ed.</role> <person-group person-group-type="editor"><name><surname>Michalos</surname> <given-names>A. C.</given-names></name></person-group> (<publisher-loc>Berlin</publisher-loc>: <publisher-name>Springer</publisher-name>), <fpage>1261</fpage>&#x2013;<lpage>1262</lpage>. <pub-id pub-id-type="doi">10.1007/978-94-007-0753-5_553</pub-id></citation></ref>
<ref id="B70"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Schiefele</surname> <given-names>U.</given-names></name></person-group> (<year>1990</year>). &#x201C;<article-title>The influence of topic interest, prior knowledge, and cognitive capabilities on text comprehension</article-title>,&#x201D; in <source><italic>Recent Research in Psychology. Learning Environments: Contributions from Dutch and German Research</italic></source>, <role>ed.</role> <person-group person-group-type="editor"><name><surname>Pieters</surname> <given-names>J. M.</given-names></name></person-group> (<publisher-loc>Berlin</publisher-loc>: <publisher-name>Springer</publisher-name>), <fpage>323</fpage>&#x2013;<lpage>338</lpage>. <pub-id pub-id-type="doi">10.1007/978-3-642-84256-6_25</pub-id></citation></ref>
<ref id="B71"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Schiefele</surname> <given-names>U.</given-names></name> <name><surname>Krapp</surname> <given-names>A.</given-names></name> <name><surname>Winteler</surname> <given-names>A.</given-names></name></person-group> (<year>1992</year>). &#x201C;<article-title>Interest as a predictor of academic achievement: a meta-analysis of research</article-title>,&#x201D; in <source><italic>The Role of Interest in Learning and Development</italic></source>, <role>eds</role> <person-group person-group-type="editor"><name><surname>Renninger</surname> <given-names>K. A.</given-names></name> <name><surname>Hidi</surname> <given-names>S.</given-names></name> <name><surname>Krapp</surname> <given-names>A.</given-names></name></person-group> (<publisher-loc>Mahwah, NJ</publisher-loc>: <publisher-name>Lawrence Erlbaum Associates, Inc.</publisher-name>), <fpage>183</fpage>&#x2013;<lpage>212</lpage>. <pub-id pub-id-type="doi">10.1542/peds.2018-3556</pub-id> <pub-id pub-id-type="pmid">31551396</pub-id></citation></ref>
<ref id="B72"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Schiefele</surname> <given-names>U.</given-names></name> <name><surname>Schreyer</surname> <given-names>I.</given-names></name></person-group> (<year>1994</year>). <article-title>Intrinsische lernmotivation und lernen. Ein &#x00FC;berblick zu ergebnissen der forschung [Intrinsic motivation to learn and learning: a review of recent research findings].</article-title> <source><italic>German J. Educ. Psychol.</italic></source> <volume>8</volume> <fpage>1</fpage>&#x2013;<lpage>13</lpage>. <pub-id pub-id-type="doi">10.1007/978-3-531-20002-6_40-1</pub-id></citation></ref>
<ref id="B73"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Schiefele</surname> <given-names>U.</given-names></name></person-group> (<year>1991</year>). <article-title>Interest, learning, and motivation.</article-title> <source><italic>Educ. Psychol.</italic></source> <volume>26</volume> <fpage>299</fpage>&#x2013;<lpage>323</lpage>. <pub-id pub-id-type="doi">10.1080/00461520.1991.9653136</pub-id></citation></ref>
<ref id="B74"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Schiefele</surname> <given-names>U.</given-names></name></person-group> (<year>2012</year>). &#x201C;<article-title>Interests and learning</article-title>,&#x201D; in <source><italic>Springer Reference. Encyclopedia of the Sciences of Learning: With 68 Tables</italic></source>, <role>ed.</role> <person-group person-group-type="editor"><name><surname>Seel</surname> <given-names>N. M.</given-names></name></person-group> (<publisher-loc>Berlin</publisher-loc>: <publisher-name>Springer</publisher-name>), <fpage>1623</fpage>&#x2013;<lpage>1626</lpage>. <pub-id pub-id-type="doi">10.1007/978-1-4419-1428-6_351</pub-id></citation></ref>
<ref id="B75"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Schiefele</surname> <given-names>U.</given-names></name> <name><surname>Krapp</surname> <given-names>A.</given-names></name></person-group> (<year>1996</year>). <article-title>Topic interest and free recall of expository text.</article-title> <source><italic>Learn. Individ. Differ.</italic></source> <volume>8</volume> <fpage>141</fpage>&#x2013;<lpage>160</lpage>. <pub-id pub-id-type="doi">10.1016/S1041-6080(96)90030-8</pub-id></citation></ref>
<ref id="B76"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Schonlau</surname> <given-names>M.</given-names></name> <name><surname>Toepoel</surname> <given-names>V.</given-names></name></person-group> (<year>2015</year>). <article-title>Straightlining in WEB survey panels over time.</article-title> <source><italic>Surv. Res. Methods</italic></source> <volume>9</volume> <fpage>125</fpage>&#x2013;<lpage>137</lpage>. <pub-id pub-id-type="doi">10.18148/SRM/2015.V9I2.6128</pub-id></citation></ref>
<ref id="B77"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Sj&#x00F6;blom</surname> <given-names>P.</given-names></name> <name><surname>Wolff</surname> <given-names>L.-A.</given-names></name></person-group> (<year>2017</year>). <article-title>&#x201C;It wouldn&#x2019;t be the same without nature&#x201D; &#x2013; the value of nature according to Finnish upper secondary school students.</article-title> <source><italic>J. Environ. Educ.</italic></source> <volume>48</volume> <fpage>322</fpage>&#x2013;<lpage>333</lpage>. <pub-id pub-id-type="doi">10.1080/00958964.2017.1367637</pub-id></citation></ref>
<ref id="B78"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Tavakol</surname> <given-names>M.</given-names></name> <name><surname>Dennick</surname> <given-names>R.</given-names></name></person-group> (<year>2011</year>). <article-title>Making sense of Cronbach&#x2019;s alpha.</article-title> <source><italic>Int. J. Med. Educ.</italic></source> <volume>2</volume> <fpage>53</fpage>&#x2013;<lpage>55</lpage>. <pub-id pub-id-type="doi">10.5116/ijme.4dfb.8dfd</pub-id> <pub-id pub-id-type="pmid">28029643</pub-id></citation></ref>
<ref id="B79"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Vilagut</surname> <given-names>G.</given-names></name></person-group> (<year>2014</year>). &#x201C;<article-title>Test-retest reliability</article-title>,&#x201D; in <source><italic>Encyclopedia of Quality of Life and Well-Being Research</italic></source>, <role>ed.</role> <person-group person-group-type="editor"><name><surname>Michalos</surname> <given-names>A. C.</given-names></name></person-group> (<publisher-loc>Berlin</publisher-loc>: <publisher-name>Springer</publisher-name>), <fpage>6622</fpage>&#x2013;<lpage>6625</lpage>. <pub-id pub-id-type="doi">10.1007/978-94-007-0753-5_3001</pub-id></citation></ref>
<ref id="B80"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Wenzel</surname> <given-names>V.</given-names></name></person-group> (<year>2016</year>). <source><italic>Konzeption und Evaluation Eines Handlungsorientierten Lernangebotes f&#x00FC;r die Primarstufe im Au&#x00DF;erschulischen Lernort Wildpark.</italic></source> <comment>Ph.D. thesis.</comment> <publisher-loc>Frankfurt am Main</publisher-loc>: <publisher-name>Goethe University</publisher-name>.</citation></ref>
<ref id="B81"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Wheaton</surname> <given-names>B.</given-names></name> <name><surname>Muthen</surname> <given-names>B.</given-names></name> <name><surname>Alwin</surname> <given-names>D. F.</given-names></name> <name><surname>Summers</surname> <given-names>G. F.</given-names></name></person-group> (<year>1977</year>). <article-title>Assessing reliability and stability in panel models.</article-title> <source><italic>Sociol. Methodol.</italic></source> <volume>8</volume>:<fpage>84</fpage>. <pub-id pub-id-type="doi">10.2307/270754</pub-id></citation></ref>
<ref id="B82"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Wiernik</surname> <given-names>B. M.</given-names></name> <name><surname>Ones</surname> <given-names>D. S.</given-names></name> <name><surname>Dilchert</surname> <given-names>S.</given-names></name></person-group> (<year>2013</year>). <article-title>Age and environmental sustainability: a meta-analysis.</article-title> <source><italic>J. Manag. Psychol.</italic></source> <volume>28</volume> <fpage>826</fpage>&#x2013;<lpage>856</lpage>. <pub-id pub-id-type="doi">10.1108/JMP-07-2013-0221</pub-id></citation></ref>
<ref id="B83"><citation citation-type="journal"><person-group person-group-type="author"><name><surname>Worthington</surname> <given-names>R. L.</given-names></name> <name><surname>Whittaker</surname> <given-names>T. A.</given-names></name></person-group> (<year>2006</year>). <article-title>Scale development research.</article-title> <source><italic>Couns. Psychol.</italic></source> <volume>34</volume> <fpage>806</fpage>&#x2013;<lpage>838</lpage>. <pub-id pub-id-type="doi">10.1177/0011000006288127</pub-id></citation></ref>
</ref-list>
</back>
</article>
