The main goal of the intervention program was to train participants to become enthusiastic, competent, literate, and responsible sportspersons and be capable of leading a team and making decisions that benefit the whole group. The intervention took place in two subsidized schools in Seville (Spain), which presented similar sociodemographic profiles and belonged to neighborhoods with an upper-middle socioeconomic level.

In Seville, federated sports clubs usually have a defined framework or guidelines for training programs. However, in clubs that are not part of a federated competition, it is common for each coach to work in his or her own way, and there is no consensus or guide on how to coach a team. In general, coaches tend to be focused on achieving victory rather than on the process of the personal development of each athlete. In the Catholic Schools Competition, where the intervention took place, they are somewhat more flexible and let the coach be the one who sets the model to follow. In this way, everything depends on the level of training and knowledge of the coach of this type of methodologies, far from those centered on execution models, typical of the courses of coaches.

This study used a convergent mixed methods design (Figure 1), because this type of design acknowledges the inadequacy of qualitative or quantitative methods alone to capture trends and details in the context of the research studies (Creswell and Creswell, 2018), so the strengths of one approach cover the weaknesses of the other, thus providing more evidence for studying the research study problem and helping to answer questions that neither quantitative nor qualitative methods alone can (Creswell and Plano Clark, 2018).

In the qualitative section, a design based on descriptive phenomenology was used (Moustakas, 1994; Giorgi, 2009), in which the researchers sought to describe the experiences lived by individuals for a specific phenomenon (Creswell and Creswell, 2018). In the quantitative section, a quasi-experimental design was used, in which there was no random assignment of participants to the experimental or control groups. This study was carried out with a pragmatic worldview, in which the focus was on the consequences of the research study and the question asked rather than the methods, thus employing multiple methods of data collection to inform the problems analyzed (Creswell and Plano Clark, 2018). This worldview is perfectly suited to the mixed methods design carried out in this work, and its philosophical assumptions are shown in Table 1.

According to the coaches, students, and schools that showed interest in, and commitment to, participating in the research study, sample selection was convenient and non-probabilistic (Patton, 2015). A total of 30 girls participated in the experimental (n = 15, age = 8.93 ± 0.80) and control groups (n = 15, age = 8.80 ± 0.86) during the 2018/2019 school year. The coach for the experimental group was a 26-year-old man with experience of 4 years in managing volleyball youth teams. The coach for the control group was a 25-year-old woman with an experience of 5 years in coaching volleyball youth teams. Both coaches were graduates in Physical Activity and Sports Sciences and had a Level 2 Volleyball Coach qualification from the Andalusian Volleyball Federation.

Both schools competed in the U-10 category in the Catholic Schools Competition, organized by the Catholic Schools Association of Seville. Both groups were selected because of their homogeneity in terms of sport (volleyball), gender (women), age (between 8 and 9 years old), training structure (two training sessions/week, 1.5 h/session, plus the weekend game), and season expectations (qualifying for the final phase of the competition). The inclusion criteria were as follows: (a) participation in the extracurricular volleyball activity at their schools; (b) willingness to participate in the study; (c) written consent of the parents/guardians; (d) attendance for at least 85% of the sessions; and (e) adequate program implementation fidelity.

This study followed the ethical commitment guidelines defined by the Declaration of Helsinki regarding the consent, confidentiality, and anonymity of the participants through an agreement signed by the boards of the schools and the parents/guardians of the players. This study was also approved by the PhD Research Committee of the Pablo de Olavide University (internal code 2345-N-20).

The dependent variables analyzed were the two dimensions of responsibility: PR, which is the responsibility to assume the own actions of an individual and act in consideration of, and respect for, the value of people and things, and SR, which is defined as sensitivity toward the feelings and needs of colleagues, respecting their rights and cooperating and working together to achieve goals and negotiating conflicts (Jiménez and Durán, 2004). Both the objective perception of the level of each of the dimensions and the subjective perception of skills development in these dimensions throughout the intervention were analyzed.

The independent variable was the TESPODEP program (Muñoz-Llerena et al., 2019), which is a hybridization of the TPSR and SE models, and was focused on the development of values such as leadership, decision-making, and PR and SR through team sports. The program, following the recommendations of Gordon (2009), used the general structure of the TPSR as a basis, adding the sport-specific elements that come from the SE, while using methodological strategies that arise from both the TPSR and SE (Table 2). A total of 37 sessions of 90 min plus 14 competition games were carried out, implementing sports content and a concrete responsibility level (Table 3). It must be considered that level 5 (transference) was implemented in all sessions of the program through the group reflection and self-evaluation, and this level was also the focus during games.

A brief description of the characteristics of the TESPODEP program is included as Supplementary Material.

For the sample selection, an informative meeting was held with the parents of all of the players in each school, explaining the characteristics of the program and the procedure to be followed for all groups (experimental and control). Subsequently, the same protocol was followed with the players and coaches from each group, with emphasis on the voluntary nature of participation. The program was implemented in groups where there were 10 or more interested players, the coach was willing to implement the program, and the parents agreed to carry it out.

The coach for the experimental group knew the fundamentals of the TPSR and SE programs and was the main person responsible for the design of the hybridization of the TESPODEP program. However, following the indications of Escartí et al. (2009, 2010b) and Fernández-Gavira et al. (2018), 1 month before the intervention he received recycling training on the theoretical foundations, objectives, and methodological aspects of both the TPSR and the SE by experts in these programs (research coauthors of this study). After the training period, the design of the intervention program was revised, with minor modifications. Throughout the intervention (once a month), the coach of the experimental group met with experts in the program to continue with the training and to analyze the fidelity of the implementation (Manzano-Sánchez and Valero-Valenzuela, 2019). The fidelity of the program implementation was considered adequate after analyzing it and triangulating the data obtained from the TARE 2.0 observation instrument (Escartí et al., 2015; Manzano-Sánchez and Valero-Valenzuela, 2019), which assessed methodological strategies, participant behavior, and the field notes.

The interviews were carried out in the final 2 weeks of training, once the program intervention had finished. The interviews were conducted with the players at the end of the session, without having established a time limit for each of them, which made it possible to collect between three and four interviews daily. The interview protocol was based on that proposed by Creswell and Creswell (2018). Interviews were recorded and transcribed verbatim. Field notes were completed daily after the training session, between 30 and 90 min after the end (depending on the availability of the researcher). All data were recorded in writing on a record sheet using the Microsoft Word (Office 365) software.

The PSRQ was completed before the beginning of the training sessions, under the supervision of the main researcher, ensuring the anonymity and sincerity of the responses, and answering any doubts that might arise during the process. Before starting, the instructions for correct completion of the PSRQ were explained and emphasis was placed on maintaining a relaxed atmosphere to promote concentration and maximum accuracy in the answers (Escartí et al., 2009, 2010a, 2011; Valero-Valenzuela et al., 2020a). The reliability in the pretest and posttest was 0.76 and 0.87 for SR and 0.83 and 0.86 for PR.

For the interview analysis, a first deductive coding was used on the basis of the existing studies and theory (Li et al., 2008; Escartí et al., 2011; Hellison, 2011) to determine the main categories of each dependent variable analyzed (PR and SR), establishing the categories of autonomy and effort (PR), and respect and caring and helping (SR). Once deductively encoded, inductive analysis of the coding was performed (Mayring, 2014). The coding frequencies for each category analyzed are shown in Table 5.

The same process as with the interviews was followed for the analysis of the field notes, starting from a first deductive coding, establishing the main categories of autonomy and effort (PR) and respect and caring and helping (SR), and subsequently applying inductive analysis. The coding frequencies with respect to each category analyzed are shown in Table 6.

The results obtained in the Kolmogorov-Smirnov normality test and the homogeneity of variances (Levene's test) showed a normal distribution of the data. The results referring to the descriptive analysis of the instruments used in the study were taken at two different moments (pretest and post-test; see Table 7). In the reliability test, some items had to be eliminated (α > 0.70) so that the PR-Pre and SR-Post factors presented adequate reliability values (α > 0.70; ω > 0.70).

In the intergroup analysis, no significant differences were observed between groups in the PR and SR variables, the magnitude of the effect size being trivial (η2 < 0.20). In the intragroup analysis, no significant improvements were observed in any group (Table 8).

The aim of the following integration was to develop integrated results and interpretations that could provide a more comprehensive understanding of the results analyzed and to validate and confirm the qualitative and quantitative results. Table 9 shows the integration of results through a joint display.

Concerning the perception of the players, practically all of them managed to develop their PR throughout the implementation. The greatest learning occurred in the effort applied to tasks and in autonomous goal setting, such that the majority perceived being able to try harder, participate more, set their own objectives and establish an action plan to achieve them, and motivate themselves in everything they do. At least half of them believed they had also learned to act autonomously and to trust themselves. These results are in line with those presented by other studies carried out with school-age participants (Stran et al., 2012; Meroño et al., 2015; Fernández-Río and Menéndez-Santurio, 2017; Antón-Candanedo and Fernández-Río, 2018) and might be caused by the methodological structure of the TESPODEP, which encourages autonomy and effort through the establishment of responsibility roles in the players, thus producing this personal development (Muñoz-Llerena et al., 2019).

In terms of SR, it seems that practically all of them developed skills related to this dimension. The greatest perceived development was shown in conflict resolution, in respect for cohabitation rules, and in helping others, capacities that are mostly considered to be capable of transferring to other contexts. To a lesser extent, several participants also improved their knowledge about interpersonal communication and relationships. These results could be attributed to the implicit characteristics of the TPSR program, because, through various aspects such as group and personal reflections or the integration of the content of responsibility in the tasks, this type of social development was promoted (Hastie and Buchanan, 2000; Gutiérrez et al., 2014; Menéndez-Santurio and Fernández-Río, 2016b, 2017; Fernández-Río and Menéndez-Santurio, 2017).

Regarding the perception of the coach, the results are in line with the insights of the players. As the intervention progressed, positive learning was observed both in PR (through the fostering of the capacity for effort, goal setting and action plans, being autonomous in tasks, and being able to train without exhaustive supervision of those responsible for the group) and SR (developing their skills of respect for others, resolving conflicts autonomously, interpersonal communication, and ability to help others and learn the importance of respecting the feelings and rights of others, the cohabitation rules, and the decisions of the group leader).

From the perception of the coach, the internalization of content and prosocial skills through group and personal reflections and self-evaluations carried out at the end of the sessions seem to be a key aspect in the acquisition of these lessons. Results in line with these perceptions have been presented in previous research studies and have been related to the perception of the teacher of the usefulness of PYD programs (Casey and Dyson, 2009; Gutiérrez et al., 2014; Manzano-Sánchez and Valero-Valenzuela, 2019) and their effect on the increase in PR and SR (Fernández-Río and Menéndez-Santurio, 2017; Menéndez-Santurio and Fernández-Río, 2017). The importance of self-reflection and critical thinking to interiorize learning has also been highlighted in the study (Stran et al., 2012).

One of the fundamental aspects that can be deduced from this study is the achievement of transference by the participants. They seem to be capable of transferring those lessons mentioned above into their daily lives. This transference is an essential characteristic of PYD programs that use sports as a means to achieve this skill transfer (Fraser-Thomas et al., 2005; Hellison et al., 2008; Hellison, 2011; Turnnidge et al., 2014; Chinkov and Holt, 2016; Whitley et al., 2016; Weiss et al., 2020). It is possible that the nature of volleyball (team sport, cooperative, etc.), together with the structure of the task assignments used based on the SE model and the methodological structuring of the TPSR, made possible the achievement of good levels of transfer in these dimensions of responsibility.

However, not all perceptions were positive. Within the PR variable, reference was made to negative or incomplete aspects of learning with respect to goal setting, autonomy, effort, participation, responsibility for the equipment, and the performance of roles. In SR, negative perceptions of learning are indicated when resolving differences between others, in interpersonal relationships, in helping others, and in respect for others. This lack of development in PR and SR, although it differs from what was previously stated, also occurred in a study based on implementations of pedagogical models in school-age participants (Gutiérrez et al., 2014). However, these considerations must be interpreted with caution, because most of them refer to specific players and situations, and not to the group as a whole. Therefore, it would be more appropriate to affirm that not all of the players had learned everything that the program can offer. Other individual social or psychological traits, as well as previous experiences practicing the sport, could have had an influence on these results.

Regarding the PSRQ, the results indicate that the intergroup (experimental and control) and intragroup (experimental) differences are not significant, and therefore, it is understood that there were no differences within or between the two groups in PR and SR when comparing before and after, although the α and ω values obtained are sufficient to accept the reliability of the instrument under the conditions used in this study (Nunnally, 1978; Campo-Arias and Oviedo, 2008). These results differ from those shown in the study (Menéndez-Santurio and Fernández-Río, 2016b; Escartí et al., 2018; Manzano-Sánchez and Valero-Valenzuela, 2019; Manzano-Sánchez et al., 2019; Valero-Valenzuela et al., 2020a), perhaps because, as a general rule, published studies always present statistically significant results. This non-significance in the data could be due to the small sample size, which might not be large enough to allow the appearance of differences between and within the groups.

In data integration, because no significant positive results were reported in the PSRQ, the results obtained at the quantitative and qualitative levels differ to a great extent. Although there are some congruent results, because not all of the players perceived improvements in all of the analyzed aspects of PR and SR, nor did the coach attribute significant development to all categories, we must be cautious in drawing conclusions due to the relativity of the results: The majority of the group seem to have developed their PR and SR, but not all of the players have developed all of the capabilities that PR and SR comprise, and not all of them are capable of using them in all the situations that might arise.

Ensuring that the integrated data are 100% congruent is a complex task (O'Cathain et al., 2007; Slonim-Nevo and Nevo, 2009). In this study, we started from a more general conception of the dimensions of PR and SR (PSRQ), and those dimensions were compared with participant learning in much more concrete and deeper aspects within those dimensions (main and secondary categories in interviews and field notes), which makes it difficult to achieve a majority of congruent results in the integration, especially if they differ so much. In this respect, the authors considered that there may be greater confidence in the results obtained at a qualitative level, because the small sample used may lead to the absence of significant results in the PSRQ, following what has been carried out in other investigations that used convergent mixed methods (Creswell and Plano Clark, 2018).

The data integration was carried out following the criteria to ensure the trustworthiness of the study. Following Creswell and Plano Clark (2018), it can be stated that both the qualitative and quantitative data were collected and analyzed rigorously, taking into account the research questions and hypotheses, because data of both types were collected based on the objectives and hypotheses raised in the study, following adequate procedures for their thematic and statistical analysis, respectively. The two types of data and their results were intentionally integrated, in line with the stated reasons for choosing a convergent mixed methods design for the study and integration of the results obtained through a joint display to later discuss the congruencies and discrepancies of the results and then draw a conclusion about them. These procedures were organized into specific research designs so that the study was undertaken in a logical way, and all elements fit together logically and consistently. These procedures were also framed within theory and philosophy, appropriately marrying the pragmatic paradigm and the PYD theory on which the study was based with the mixed methods designs used. These criteria have been taken into account in multiple studies that use mixed methods to ensure their reliability (Ames et al., 2009; Craig et al., 2019; Vázquez-Diz et al., 2019; Leiter et al., 2020; Valero-Valenzuela et al., 2020a; Weiss et al., 2020).

This study helps to fill the gap in the study related to the effects of SBPYD programs in competitive settings by designing a hybrid program that could serve as a reference in team sports interventions based on PYD. Another strength of this research study is its contribution to the mixed methods research field, which is not widely used in competitive sports interventions.

From a practical view, this study may provide strategies for coaches and teachers in the design and implementation of training exercises that aim to enhance decision-making, leadership, and life skills, transferring them to the daily lives of the participants. At early ages, these improvements can be difficult to achieve, so the coach should create learning environments to improve these capabilities. TESPODEP is a well-structured intervention program that aims to overcome these limitations, providing useful guidelines for coaches. Some recommendations to coaches when intervening within the competitive sport could be as follows: (a) set two different types of goals, sportive goals, and life skill goals; (b) integrate PYD strategies into training tasks; (c) use the methodological strategies offered to facilitate fostering PYD and life skill learning; (d) make all players play all roles throughout the season and let them make their own decisions; and (e) keep a balance between sports results and PYD intervention.

This study has some limitations. The main limitation is the sample size, which, although it presents an adequate and sufficient size to obtain relevant information for the scientific community at a qualitative level, seems to be insufficient to obtain significant results at a quantitative level (Creswell and Creswell, 2018; Creswell and Plano Clark, 2018). It should also be noted that this study was carried out with only one experimental group, in a specific sociocultural and socioeconomic context, in a single sport, and in a single category (limited age range) and competitive level. In addition, all of the participants were girls. This means that it is not possible to determine whether there are differences between genders, ages, sports, levels of sports demand, or socioeconomic/sociocultural levels.

To alleviate the limitations of this study, the following lines for future research studies are recommended: (a) to increase the sample size to draw on statistical data that contribute to a better understanding of the research question; (b) to carry out the study in different team sports, ages, competitive levels, and/or socioeconomic/sociocultural levels to determine how TESPODEP works in different samples and settings; and (c) to include both genders in the sample to determine differences between genders in terms of life skill acquisition.