Reading is an essential human skill (Ritchie and Bates, 2013) and a fundamental goal for elementary students. The ability to read is a critical for opening knowledge spaces, in such a way that public authorities around the world have focused on promoting reading practices and skills starting in early childhood education [see the Program for International Student Assessment (PISA), and the Progress in International Reading Literacy Study (PIRLS); Mullis and Martin, 2015; Organisation for Economic Co-operation and Development, OECD, 2019; Rosa et al., 2020].

However, the worldwide COVID-19 pandemic challenged educational practices, having a significant impact on the teaching-learning process (Reimer et al., 2021). Face-to-face instruction was abruptly halted, and many schools were forced to provide emergency remote learning (Flores et al., 2022). In Portugal, this scenario occurred with two successive lockdowns, the first between March-September 2020, and the second between January and March 2021. Teachers and parents struggled to balance formal and informal education during these periods (Daniel, 2020; Hodges et al., 2020; Reich et al., 2020), and family houses were converted into schooling environments. The disruptions prompted by the COVID-19 pandemic in educational settings, specifically with the adoption of distance/online learning, changes in teaching practices, and increased stress (Meinck et al., 2022), intensified challenges associated with the process of learning to read. Empirical data suggest that lockdowns had a significant impact on students’ reading skills in their early years (Wyse et al., 2020). One reason for this is that many students spent less time engaged in formal learning during school shutdowns than they did during face-to-face instruction, which means they spent less time reading—and learning to read (Huber and Helm, 2020; König et al., 2020). In the Portuguese case, such challenges may have been especially difficult for primary school children, particularly those in the early grades, because children learn to read in the first grade, consolidate their reading skills in the following one and are expected to have achieved reading competency by the 4th grade. Thus, being actively engaged with reading (in and outside school) is critical. To meet these challenges teachers had to develop alternative modes of teaching instruction to encourage students reading abilities. Lin et al. (2017) found that using digital tools (such as app’s, software programs, smartphones, and tablets) can boost learning motivation by keeping students’ attention and focus on their learning process even when faced with difficult situations. Students’ motivation and focus are especially important when we consider that, unlike oral language, learning to read is a process that does not occur naturally as a result of exposure to written material or information or words (Sim-Sim, 2009). It assumes the adoption of strategies through explicit, consistent, and systematized teaching practices, demanding the use of specific methodologies and allowing adequate time for learning and training. The first years of school are deemed pivotal in the process of learning to read, and they are frequently marked by families and teacher’s high expectations regarding children’s success (Stern, 2006; Cruz et al., 2022). It is also during the first years of formal education that learning difficulties associated with reading emerge, highlighting the relevance of early assessment and intervention so that students have a better chance of overcoming them. Reading difficulties can have a negative impact on children’s learning and development trajectories, such that children who struggle with reading in primary school are more likely to struggle through high school (Roberts et al., 2022), putting them at higher risk of dropping out (Hernandez, 2011). A growing body of research indicates that early interventions are effective in preventing these negative outcomes, emphasizing the importance of developing early intervention programs that systematically promote and assess reading abilities in the classroom (Lyytinen and Erskine, 2016; Hall and Burns, 2018; Raspin et al., 2019). Primary school grades (such as the 2nd and 4th grades) provide a unique developmental window in which children are more sensitive to the effects of reading interventions, particularly when delivered earlier (Al Otaiba et al., 2009; Lovett et al., 2017; Wanzek et al., 2018).

In parallel, research has also highlighted the role played by individual differences in reading difficulties. One of the most debated dimensions has been children’s gender. Literature has consistently described girls as having better reading ability than boys (McKenna et al., 1995; Logan and Johnston, 2009; Below and Sorrell, 2010; Sochacka, 2014). This gender difference has been found in different countries and cultures (van Hek et al., 2019). In PISA and PIRLS reports on reading in students (Rosa et al., 2020), girls are consistently reported as having a significant advantage over boys in terms of reading performance across all OECD countries (van Hek et al., 2019). However, when considering reading fluency and accuracy in primary school years the results appear to be inconsistent. While Abd Ghani et al. (2020) reported no statistically significant gender differences when analyzing reading fluency in 2nd grade children, Sochacka (2014) and Solheim et al. (2021) found significant gender differences in first graders’ reading fluency and accuracy, favoring girls. This ambiguity of findings supports the need for additional research into potential gender differences in reading fluency and accuracy, particularly in primary education level.

Reading entails both decoding written words and comprehending their meaning (Suggate, 2016). Such a complex process highlights the task’s difficulty as well as the importance of encouraging the automation of the deciphering process in order to free the child to comprehend what he or she is reading (Schwanenflugel et al., 2006). With automatic word and sentence recognition, more cognitive resources are available to engage in higher-level thinking processes, which are frequently critical for reading comprehension (Zimmerman et al., 2019). Thus, reading comprehension is dependent on the ability to combine fluency of reading (the number of words read per minute in a text) with accuracy (the absence of errors) and prosody (cadence, intonation, and rhythm) (Zimmerman et al., 2019). Given the focus of the current study, we will now explore further the fluency and accuracy reading dimensions or skills.

Fluency is linked with reading comprehension and can be defined as the ability to read a text quickly, accurately and expressively (Gersten et al., 2020). Fluent readers can identify words accurately and automatically, allowing them to focus their attention on reading comprehension and in the connections between the ideas presented in a text and their prior knowledge (National Institute of Child Health and Human Development, 2000). Less fluent readers, on the other hand, must focus their attention on word recognition, resulting in less attention devoted to reading comprehension. As a result, while the ability to read words accurately is required in the process of learning to read, the fluency with which this process is carried out is critical for children’s reading comprehension (Gersten et al., 2020). Rasinski et al. (2011) suggest that fluent readers tend to have more positive attitudes toward reading, as well as a more positive perception of themselves as readers. As a result, fluent readers are more likely to read more, learn more, and further improve their reading skills. In addition, fluent readers can serve as good reading models and assist other learners in the process of learning to read. Fluency assessment is also an important indicator of general reading competence in the school context, and it is directly related to reading comprehension (Zimmerman et al., 2019; Sucena et al., 2022). The recognition of a list of related words and a text reading are two strategies commonly used to assess reading fluency (Meeks et al., 2014; Martens et al., 2019). Following Martins and Capellini (2021), fluency performance can be analyzed calculating the reading percentile, with results above the 55th percentile considered average. Strategies such as reading aloud, repeated reading of a small excerpt of a text, and peer-tutoring have all been shown to be effective in improving reading fluency (National Institute of Child Health and Human Development, 2000; Oddo et al., 2010). In fact, research suggests that to promote the development of reading fluency, teachers should provide students with numerous opportunities for reading practice, preferably with guidance from more fluent readers (e.g., teachers, peers, or parents) who comment on the readings and help them to become aware of their mistakes and correct them (Beach and Traga Philippakos, 2021; Zimmermann et al., 2021). Hence, systematic and deliberate practice of activities that promote mastery of the alphabetic principle, as well as holistic activities that allow students to anticipate and comprehend meaningful messages, are good practices for developing reading fluency (Sim-Sim, 2009; Carvalho, 2011). In terms of written material, reading a text is thought to be a more accurate predictor of fluency (Wanzek et al., 2016). There have been few studies that analyze reading fluency in European Portuguese primary school children (Fernandes et al., 2017; Cruz et al., 2022). Key findings highlight the influence of word recognition skills in the development of reading fluency, as well as the intrinsic relationship between the latter and vocabulary acquisition, particularly in the early grades (Fernandes et al., 2017). At the same time, Serrano et al. (2011) emphasize the 2nd grade as critical for establishing a more abstract representation of the spelling system in Portuguese children, underscoring the potential impact that early reading fluency interventions may have on subsequent reading competency development.

The reader’s precision in orally representing words from their orthographic forms, on the other hand, is referred to as accuracy (National Institute of Child Health and Human Development, 2000; Zimmerman et al., 2019). However, reading fluency cannot be achieved solely through reading accuracy. The speed and ease of word recognition (i.e., automaticity) emerge later as the learner’s instant recognition repertoire becomes embedded. Reading accuracy then refers to the reader’s ability to “produce an accurate oral representation of words in text from their orthographic forms” (Zimmerman et al., 2019, p. 73), i.e., to correctly recognize or decode words. According to Hudson et al. (2005), a strong understanding of the alphabetic principle, the dexterity to combine different sounds, and knowledge of a large number of words are at the heart of reading accuracy. Low word recognition accuracy has a negative impact on reading fluency, potentially leading to text misinterpretation. Thus, accurate word decoding is required for fluency (Lopes et al., 2014; Borges and Viana, 2020). The percentage of correct words read by the reader is deemed as a good indicator of reading accuracy (Carvalho, 2011; Rasinski et al., 2011). In this regard, Rasinski (2004) identified three levels of accuracy performance: independence level (97–100% of accuracy; i.e., the student can read the assessment text autonomously, without assistance); instruction level (90–96% of accuracy; i.e., the student can read the text, but still requires some assistance, as some errors are not noticed); and the frustration level (below 90% of accuracy; i.e., even with assistance, the student finds reading the text or another material of similar difficulty very challenging, and cannot track most decoding errors, often needing several attempts before decoding certain words). Contrary to what is observed in reading fluency studies, very few research has focused on gender differences in reading accuracy, particularly in the early school years. Research on the development of reading accuracy in European Portuguese readers is also scant (Seymour et al., 2003; Cadime et al., 2021; Cruz et al., 2022). Findings suggest that Portuguese first grade readers have lower reading accuracy levels than other European readers, with levels significantly lower than 90% (Seymour et al., 2003). Thus, research exploring changes in reading accuracy across subsequent grades level is especially important for determining whether reading accuracy is still developing or if a real difficulty is already emerging so early on.

Recent meta-analyses show that a plethora of variables influence the efficacy of the strategies and interventions used for reading fluency and accuracy (Gersten et al., 2020; Kim et al., 2020; Zimmermann et al., 2021). These include the duration of the intervention, the number of sessions, the session length, and the size of the group. Scripted, short interventions (i.e., between 10 and 100 sessions), that take 10–60 min and happen 3 or 5 times a week in small groups of students (i.e., two to five students) with similar academic needs, have consistently emerged as effective in promoting reading competency (Wanzek et al., 2016; Gersten et al., 2020; Kim et al., 2020).

Among these interventions, peer tutoring has proven to be effective in improving students’ reading fluency and accuracy (Blanch et al., 2012; Topping et al., 2016; Alzahrani and Leko, 2018; Duran et al., 2019). Peer tutoring is a system whereby learners help each other and learn by teaching. It is a process in which more advanced learners, not necessarily teachers, helpless advanced learners in an interactive, systematic and meaningful way, often used on a one-to-one basis, that is, between peers (Topping et al., 2016). In comparison to formal education, peer tutoring allows more opportunities for practice while also providing guidance, personalized feedback, and assistance in resolving misinterpretations (Casanova, 2012; Sytsma et al., 2019; Lee and Szczerbinski, 2021). It can also encourage more reflection on the learning process, leading to high levels of self-regulation and agency over one’s learning process. It can promote the development of study skills, foster learning autonomy, and nurture the “learning to learn” capacity in the cognitive development scope. Furthermore, it can promote the ability to deal with uncertainty in a less anxious manner, significantly contributing to higher levels of emotional self-regulation and, ultimately, to the overall learning process (Forbes-Riley et al., 2008).

Casanova (2012) implemented a peer tutoring intervention by pairing children of similar ages and educational levels. Even though the participants are in an asymmetrical relationship, they share similar characteristics and a common goal. The peer tutoring process has been shown to benefit both the tutor and the tutored because it can improve the former’s self-esteem, self-confidence, perspective-taking, and metacognitive abilities, to name a few (Casanova, 2012). Moreover, peer tutoring can have both a preventive and a remedial effect, anticipating developmental obstacles (and encouraging a proactive attitude toward them) while also assisting in their resolution. Jones et al. (2017) studied the effects of a peer-tutoring reading intervention in early primary grades and found positive and significant effects on children’s reading fluency. Moreover, Fuchs et al. (2000) obtained positive and significant effects on first grade children’s reading accuracy involved in peer-tutoring reading intervention.

To ensure the quality and success of peer tutoring, however, it is critical to clearly define the procedures, schedules, and spaces to be used during tutoring, as well as to clarify the peer tutoring process to the peer-tutor and the peer-tutored, teaching them general mentoring skills. It is also critical to monitor the quality of the peer relationship, provide peer role rotation, and ensure continuous process evaluation (Sanches Ferreira and Santos, 1994; Topping et al., 2016).

With the challenges imposed by the COVID-19 pandemic (Reimer et al., 2021), a new variable has been introduced into the traditional reading skills interventions: online learning methods and tools, which have risen to the forefront of educational systems worldwide. However, research on how the pandemic may have influenced children’s reading performance is still limited, both in typical and struggling readers, with only a few studies examining the effects of online education and interventions (Alves and Romig, 2021; Beach and Traga Philippakos, 2021), implying that more research is needed to investigate the efficacy of online reading interventions. Furthermore, given the importance of reading in shaping students’ learning and developmental paths, providing teachers with strategies that promote reading within favorable learning educational contexts should be one of education’s primary concerns. In this regard, the purpose of this study is to assess the impact of implementing an online peer tutoring intervention on the development of fluency and accuracy reading skills in primary school students. Given that Portuguese children begin learning to read in first grade, consolidate their abilities in 2nd and complete their learning to read cycle in 4th grade, we chose to include only 2nd and 4th graders (with and without the need for universal and selective measures to support learning and inclusion)¹ because it would allow us to better understand and differentiate gains in the reading development process.

The study aims to answer the following three research questions: (1) What is the effect of the online peer-tutoring intervention on students’ reading fluency and accuracy? (2) To what extent do students’ reading fluency and accuracy change during the intervention period? (3) To what extent can the intervention effects be attributed to grade level (G2, G4), gender and pre-intervention reading performance level (i.e., frustration level or not)?

This study aimed at assessing the impact of an online peer tutoring intervention on the development of fluency and accuracy reading skills of elementary school students (2nd and 4th graders). In line with previous findings (Blanch et al., 2012; Topping et al., 2016), our study showed that the combined intervention significantly contributed to the students’ progress in their reading abilities, that is he intervention was effective for three classrooms, when the two other classrooms functioned as the control group. To corroborate these findings no significant effects of “no intervention” were found, when controlling for pre-test scores, that is Class E, that started the intervention in week 13–14 and therefore was more time in the waiting list did not registered a higher improvement in reading skills than class D. Despite having no statistical significance, slight improvements were verified in these two classes on accuracy and reading fluency before starting the intervention. This indicates that getting instruction by teachers is important to support students in improving their reading, but implementing interventions, such as online peer tutoring can maximize what students get in school curriculum. Reading in pairs constitutes an opportunity to increase the time for reading practice with an audience, which is a common challenge for elementary teachers in a typical day in the classroom (Alzahrani and Leko, 2018; Sytsma et al., 2019). This challenge became particular evident during the successive lockdowns during the COVID-19 pandemic, which demanded alternative ways to assure teaching learning processes (Chetty et al., 2020; Kuhfeld et al., 2020; Flores et al., 2021). Therefore, the relationship between the use of digital tools and the teaching-learning process has become increasingly important (Jamshidifarsani et al., 2019; Dúo-Terrón et al., 2022) justifying additional research.

Results revealed a statistically significant, large effect difference between the three measurement moments in terms of reading fluency and accuracy. Accuracy gains between pre and post-test were significant higher for students that were in the frustration level (low performance) in reading accuracy before the intervention. The use of three-measurement point procedure allowed the analysis of the stability of the development of reading accuracy and fluency, suggesting that for accuracy, having a peer aside is a more proficient peer is important to support children in identifying mistakes and correct them. In particular, peer tutoring intervention seems to be a particular relevant intervention for children who need extra support to decode words.

On regard to fluency gains, differences were not found between pre and post-test measurement points. Instead, the increase in fluency scores between pre-test and intermediate scores were significantly greater for 4th grade than for 2nd grade students and the increase between intermediate and post-test scores was significantly higher for 2nd grade than for 4th grade students. These results suggest that older students demonstrated effects of the intervention soon after its initiation, but these tended to stabilize, while younger students took longer to demonstrate results, but the growth was greater from the middle of the intervention. These findings seem to reveal that 4th graders are at other phase, they are more mature, so they seem to reach their potential earlier in the intervention, while 2nd graders are just developing their fluency skills.

Therefore, it seems relevant that the implementation of the reading promoting intervention through peer tutoring has contributed to an effective increase in children’s accuracy and fluency indices. Results also indicates that these type of intervention can be beneficial for all students, but mainly for students with lower performance in reading and therefore with additional needs of supports. Those who read better, read more, increasing the probability of developing the competence to extract and construct meaning in the interaction with texts, as well as of expanding lexical development, which broadens world-knowledge, and diversifies cognitive and metacognitive strategies (Stern, 2006; Cruz et al., 2022). Furthermore, the fluency gains in 2nd graders found in this study reinforce the importance of placing emphasis on additional interventions in the early years of learning, such as online peer tutoring, that reinforce the pedagogical strategies used by teachers in the classroom. It should be noted that this intervention was implemented with all students and can be used as a universal educational measure, requiring no special and overly demanding adjustments.

Interestingly, analyses in this study demonstrate no significant mean differences for gender. This finding suggest that the gains of boys and girls in reading skills, such as fluency and accuracy, throughout the online peer tutoring intervention are comparable. Despite the results of other studies documenting that girls tend to present higher reading skills (Sochacka, 2014; van Hek et al., 2019; Solheim et al., 2021), these data demonstrate that the interventions have similar benefits for both groups.

However, there are limitations to this study that must be considered and ideally overcome in future studies. Due to the sample size, the results cannot be generalized to the general population. In fact, it is necessary to replicate this study with a representative sample to overcome this limitation. It is also advisable to use a sample that includes a representative number of students identified with additional support needs. Students in the waitlist-control group had more experience with the test format than children in the intervention groups. Another limiting aspect concerns the time limitation for data collection and the lack of a follow-up to further explore the effects of the intervention. Finally, it is important to note that despite parents were asked not to interfere in the peer tutoring activity, this fact cannot be completed assured.

Despite the study’s limitations, the findings support the positive impact that online peer tutoring can have on the promotion of students’ reading abilities. Overall, given the online peer tutoring format, the current study may pose a relevant contribution to the ongoing discussion about the development of effective strategies to promote reading abilities in the first years of school.

The raw data supporting the conclusions of this article will be made available by the authors upon reasonable request.

Ethical review and approval was not required for the study on human participants in accordance with the local legislation and institutional requirements. Written informed consent to participate in this study was provided by the participants’ legal guardian/next of kin.

MS-F: conceptualization, study design, data analysis, and article editing and review. HM: conceptualization, data collection, and article editing. AV: data analysis and article writing. SA: study design, data analysis, and article writing. All authors contributed to the article and approved the submitted version.