Implementing Positive Youth Development in Primary Physical Education: The Learning Trajectories of a Physical Education Department Head Fomentar el Desarrollo Positivo de los Jóvenes en la Educación Física Primaria: Las Trayectorias de Aprendizaje de un Coordinador del Departamento de Educación Física

To date no research has investigated the key mediation role of PE department heads in the successful implementation of Positive Youth Development (PYD) programmes. Thus, the purpose of this study was to examine the effects of a PYDbased intervention in the learning trajectory of a PE department head leading the implementation of a PYD programme. A PYD intervention was conducted over four months, which included several cycles of theoretical inputs interspersed with a series of PYD field applications. The principal participant in this study was an experienced PE department head who was supervising the work of 63 primary school PE teachers. Findings showed the PE department head progressed from a perspective of PYD as an inherent and naturally emerging outcome to an understanding of PYD as more structured programmes of activities that include a deliberate approach. Further research is needed to uncover effective mediation strategies that can best support the implementation of PYD at an institutional level.


Introduction
Physical education (PE) is expected to foster several positive developmental outcomes (e.g., personal development, relational skills) that may help children strive and reach adulthood ready for society's social challenges (Martinek & Hellison, 2009). Several curricular programmes (Weiss, 2011) clearly state how PE should be conducive to 2020, Retos, 38, 528-536 © Copyright: Federación Española de Asociaciones de Docentes de Educación Física (FEADEF) ISSN: Edición impresa: 1579-1726. Edición Web: 1988-2041 Positive Youth Development (PYD) outcomes throughout learners' developmental spectrum (Cascales & Prieto, 2019;Molina, 2018;Vivas, Gómez, Bartoll, & Miravet, 2017). PYD is an asset-based approach that acknowledges the need of intentionally developing a broad range of positive skills such as respect, empathy, and goal setting in order to maximize youth's chances of developing life skills (e.g., perseverance, leadership) (Lerner, Almerigi, Theokas, & Lerner, 2005). PYD encompasses a broad range of instructional models and intervention programs that have been designed to foster life skills as key developmental outcomes (Hellison, 2011). For example, Hellison (2011) also developed an instructional model called the Teaching Personal and Social Responsibility model to intentionally teach responsibility to youth through PE. Life skills have been defined as positive skills such as focus, leadership and emotional control crucial in and outside PE that may help youth to deal with many social challenges and flourish (Pierce, Gould, & Camiré, 2017). PE has been considered a valuable platform to generate this type of outcomes and better prepare youth for adulthood and life in society. However, PE teachers' role in fostering PYD is a complex process as it involves «quality programme design» comprising «sequenced, active, focused, and explicit activities» (Bean et al., 2018, p. 5). Recently, Santos, Neves and Parker (2020) recognized the need to develop a more indepth understanding about PE teachers' role in fostering PYD so more evidence-based practices are available.
Recent work by Pozo, Grao-Cruces, and Pérez-Ordás (2018) provided a comprehensive review of research on PYD within PE. Overall, a positive trend of successful development of PYD in schools was found and teachers' positive dispositions to welcome the implementation of PYD activities. Moreover, the bulk of research on PYD through PE has been mainly focused on the impact of programme delivery on students PYD outcomes (e.g., Walsh, 2008;Walsh, Ozaeta, & Wright, 2010), and on teachers' and students' perceptions about the dilemmas and constraints experienced during implementation of PYD-based programmes (e.g., Hemphill, Templin, & Wright, 2015) in a number of different PE settings and countries (e.g., underserved communities, school-based projects) (e.g., Gordon, Thevenard, & Hodis, 2012). Jung and Wright (2012) conducted a study in a South Korean middle school targeting underserved youth at risk of school failure. Overall, the PYD-based program implemented proved to be an effective tool to promote personal and social responsibility development. However, self-direction was considered difficult to foster due to the cultural characteristics of this setting in which a more controlling approach was commonly used. Gordon, Thevenard and Hodis (2012) conducted a study to understand how New Zealand PE teachers intervening in 148 local secondary schools implemented a PYD-based program. Findings showed how most PE teachers believed the program fostered personal and social responsibility outcomes. Culturally diverse school settings could be further explored to understand the processes that influence how PYD is embedded within PE.
Although many studies have highlighted how PYD outcomes are heavily influenced by particular circumstances within the learning contexts (Santos et al., 2020) in which they are implemented (e.g., underserved youth at risk of school failure), a realized shortcoming of the existent research on PYD was that very few studies have been conducted in non-English speaking countries. Future research could attempt to fill in this gap of knowledge deemed critical (Pozo et al., 2018) to understand how different curricula, teacher education programmes and cultural idiosyncrasies have different impact on the implementation and effective development of PYD outcomes in PE.
In reference to the implementation of PYD programmes at a school institutional level, several authors have highlighted the importance of PE department heads and PE teachers in providing solid grounds to create effective PYD learning environments (e.g., Jung & Wright, 2012). In many educational contexts, PE department heads are responsible for designing the curriculum, as well as supervising program delivery and PE teachers' implementation. Typically, PE department heads that work in city councils only supervise extracurricular activities that complement PE classes as the ministry of education oversees the quality of compulsory PE classes. Further, in light of the particular organizational structure of many institutions that are responsible for administrating PE programmes (e.g., city councils/local councils), Martinek and Hellison (2009) assert that a «more widely supported and embraced» implementation of PYDbased programmes (Jung & Wright, 2012, p.1560 requires not only the active engagement of PE teachers and students but also the solid top-down integration in the process of other key stakeholders (i.e., PE departments heads). However, those very few studies focused on the institutional implementation of PYD programmes have shown that most initiatives of school organizations and governing bodies adopted an implicit approach towards PYD. An implicit approach to PYD involves the implementation of few concrete strategies, activities and objectives (Bean, Kramers, Forneris, & Camiré, 2018;Holt et al., 2017). Specific pedagogical and strategic guidelines or continual guidance for PYD programme implementation have seldom been provided to PE teachers during their journey to implement PYD (Hellison, 2011). In this regard, a PE department head plays a particularly significant role in providing momentum and securing sustainability of any PYD-based programme (Jung & Wright, 2012). First, a key function of a PE department head is to mediate the translation of the educational philosophy of the institution (e.g., school) into specific and applicable programmes that positively influence the practice of PE teachers. Second, in that process, PE department heads are required to actively influence PE teachers' behaviors, mediate the collaborative construction of a coherent, sequenced and relevant plan of PYD activities, and put structures in place that guarantee effective programme implementation (Walsh et al., 2010). Nonetheless, to our knowledge, not a single study has to date examined the challenges and barriers faced by a PE department head during the process of helping other PE teachers implement a PYD programme (Wright, Jacobs, Ressler, & Jung, 2016).

A Learning Trajectory Framework
Research indicates that knowledge of individuals' trajectories of thinking, learning and development in a given subject-matter or work-based activity can be an effective way to inform about best practices of curriculum and intervention design (e.g., effective PYD-based intervention protocols) (Casey, & MacPhail, 2018). Specifically, in the present study an in-depth examination of the 'Learning trajectory' of a PE department head was hypothesized to be a very useful means to inform about potential practices that might help PE teachers effectively promote development of PYD outcomes. Clements and Sarama (2004) conceptualized a 'Learning trajectory' framework as a developmental narrative of individuals' progress in a specific professional domain or activity. The learning trajectories are typically conceptualized or created by small groups or individual teachers, so they are based on more intimate knowledge of the particular educational agents involved -their extant knowledge and learning preferences, while engaging in particular task types or social interaction contexts that influence a developmental sequence. Thus, «a hypothetical learning trajectory» includes three mutually influential features that are dynamically (re)shaped throughout time: (i) the developmental 'goals' established for the intervention, (ii) the 'matching activities' designed and put in place to operationalize such goal achievement, and (iii) a 'developmental progression' or sequence. As an inextricable element in a learning trajectory, there is an explicit determination and mapping of the features in the process that are designed to engender knowledge and progress at the given domain (e.g., PYD). For example, there is a focus on the route of mediation strategies (e.g., instruction scaffolding by a facilitator) or specific tasks employed (e.g., workshop content) (i.e., matching activities) to help develop the thinking and learning in which the individuals might engage during their path toward supporting achievement of the specific goals at different levels of thinking and progress (the 'developmental sequence' or 'progression') (Clements & Sarama, 2004, p. 82).
The learning trajectory approach has been used mainly to research on mathematics education (Clements & Sarama, 2004). In the specific field of PE, the study of Casey and MacPhail (2018) is the sole research that attempted to provide novel insight on how a learning trajectory study sheds light on the developmental trajectories of teachers. Similarly to Casey and MacPhail (2018), this study sought insight of the activities that might enhance a teacher's pedagogical journey «towards supporting a model-based approach to teaching PE» (p. 14). For this purpose, there were two dimensions of analysis followed in the present case study. First, this case study sought information on the evolving strategies used to facilitate the leadership of a PE department head during the implementation of a PYD programme. Second, it composed a narrative of the learning trajectory of a PE department head during the process of learning about PYD and in his mediation of the implementation of PYD activities by the PE teachers in his department. Therefore, the purpose of this study was to examine the effects of a PYD-based intervention in the learning trajectory of a PE department head leading the implementation of a PYD programme.

Setting
In the Portuguese educational context, PE-based programmes are delivered differently across the curriculum. While PE is a compulsory subject throughout the curriculum and delivered by professional teachers (i.e., teachers holding teaching certificates), extracurricular activities for children ranging between 6 and 10 years old are not compulsory. Although not required, most professionals teaching extracurricular activities are certified teachers. Extracurricular activities (e.g., English language, arts, physical and sport activities) in primary school are delivered to children ranging from 6 to 10 years old twice a week. These extracurricular physical and sport activities modules (that complement PE sessions) are optional and managed by PE department heads working in city halls. As common practice, a PE department head is someone with substantial experience in PE and is appointed to oversee the practice of all PE teachers working within extracurricular activities conducted in primary schools. In these cases, PE department heads have a critical role in assuring programme quality in these contexts as they supervise PE teachers and help them implement activities and strategies conducive to PYD outcomes. The present study took place in one of the largest city halls in the country located in the north of Portugal. There were 20 primary schools in the council, 63 PE teachers and over 400 students that were indirectly involved in this study.

Participants
Peter (pseudonym), a male 41-year old PE department head was the principal participant of the present study. Peter has a master's degree in teaching PE and has been a PE department head for nine years. He has also nine years of experience i teaching PE in public schools. During the school year in which the present study was conducted, Peter exercised exclusively administrative tasks related to the supervision of the PE teachers' practices. Prior to the study, Peter had never taken part in any PYD-based intervention, both as a city hall representative and/or as a PE school teacher. A 31-year old researcher with six years of experience in this field was responsible for coaching Peter to develop a PYD approach.

The PYD intervention
In this case study, the research team designed an intervention protocol to help Peter deepen his knowledge about PYD and learn how to coach PE teachers to implement a PYD approach. An expert on PYD acted as a 'facilitator' of Peter's supervision of the PYD programme field implementation. The intervention included four PYD-focused theoretical and practical inputs (workshops) conducted over four months (see Figure 1). Concurrently to the workshops Peter implemented PYD materials.
All the decisions made throughout the design and ongoing (re)shaping of the PYD-focused intervention were performed based on discussions and collaborative reflection with the co-authors, who were experts on PYD and/or sport pedagogy. A reflexive approach (Cunliffe, 2004) was deemed appropriate to help Peter provide insight on his beliefs, practices and perceived challenges throughout the PYD intervention. In order to facilitate reflection, all the sessions were audio and video recorded and made accessible to Peter.

Procedures
Before data collection, clearance to conduct the present study was attained through the city hall where Peter worked. This study was also approved by a research centre as part of a larger research project. The participant was debriefed about the study's objectives, scope and implications and accepted to take part in this study. Several informal meetings were used to discuss the research design, objectives and advantages for the city hall, due to the novel nature of PYD for school organizations in Portugal. The PYD workshop and interviews where scheduled at a mutually convenient time and place.

Instruments
Workshops. In total, four workshops were conducted from March to June (see Figure 1). The workshops served simultaneously as core data sources and as forums of content delivery on PYD and on potential strategies that might best help Peter's supervision of PE teachers efforts towards PYD. The first workshop aimed at understanding Peter's philosophy and past and current practices as a PE department head (e.g., What should be the main goal of primary school PE and the role of PE teachers? How would you define your teaching philosophy/conception?). It also comprised an initial theoretical clarification of core PYD concepts and teaching practices, the anticipation of potential challenges and barriers to PYD implementation (e.g., What might be the main challenges you need to overcome to promote your PE teachers' implementation of PYD?), and Peter's initial goals and planned matching activities as a PE department head (e.g., What goals will you be setting for the start of the programme and why?).
Throughout the intervention, a focus was placed on Peter's perceived changes in his conceptualization and pedagogical understanding of PYD (e.g., How would you define PYD?; How do you think PYD could guide PE teachers?), the challenges experienced in the role of supervisor of PE teachers' implementation of PYD (e.g., What were the main challenges of working with teachers?), and overall perceptions on the PYD-focused intervention experience (e.g., What strategies have you learned that are useful to supervise the PE teachers' implementation of PYD?).
Reflexive Diary. Peter kept a reflexive diary (Alexandrache, 2014) before and throughout the PYD intervention in which all the documents shared with the PE teachers were included, as well as reflections about: (a) the interactions maintained with the expert on PYD and the department's PE teachers, (b) a detailed account of his experiences throughout course delivery, outcomes attained through the course and (c) a vivid report of specific case studies (i.e., experiences with certain PE teachers).
Peter was provided with a sample structure for the reflexive journal in order to guide his reflections and develop reflexive routines. The following guiding questions were included: (a) What PYD outcomes did you work on today?; (b) What strategies did you use?; (c) What challenges did you face?; (d) What would you change in your philosophy and practice after today?; (c) Could you comment on specific PE teachers PYD behaviors?. The participant was invited to add sections to this structure and comment freely on his own lived experiences more autonomously. The reflexive journal was shared frequently with the first author and helped shape the contents included in the workshops, and also included facilitator's notes and reflections derived from the informal contacts with the participant.
Research log. The course facilitator kept a research log throughout the PYD intervention. The log contained a detailed chronological record of critical events related to Peter's training of the PE department head as supervisor of the PYD programme field implementation. The establishment of goals and related matching activities set by the facilitator were based on content analysis of the ongoing exchange with Peter on the continual examination of Peter's reflexive diary.
Semi-structured Interview. A semi-structured interview was conducted with Peter at the end of the PYD intervention. This event provided a reflexive summary of the achievements and barriers to the programme's implementation and future plans toward promoting a sustainable implementation of PYD at an institutional level.

Data analysis
All the data was transcribed by the first author and read multiple times to enable 'data immersion' (Silverman, 2000). A thematic analysis was deemed appropriate to find patterns within the data having in mind the purpose of this study. The researchers guided by Sparkes and Smith (2016) attempted to describe the participant's lived experiences through different data sources. Several analytical steps were taken based on a six-stage model proposed by Braun, Clarke and Weate (2016). First, raw data was segmented into low order themes (e.g., positive outcomes). Then, low order themes were grouped in a hierarchical manner and included into three high order themes (e.g., goal, developmental sequence, matching activities). Finally, the themes were revised and refined for internal homogeneity and external heterogeneity by all the authors. An inductive (i.e., data-driven) and deductive (theory-driven) analysis was conducted to generate patterns within the dataset and use Clements and Sarama´s (2003) learning trajectory framework. These quotes were translated to the English language by the first author with help of the second author who were both fluent in Portuguese and English.
The quality of the research was assured following a set of procedures based on the characteristics of this study. In a process described by Smith and McGannon (2017) and Smith (2018), the authors attempted to attain transparency by describing the PYD-focused intervention and all the steps associated to course delivery, the teaching context in Portuguese primary schools, data collection and data analysis procedures, and the course facilitator's and Peter's experiences. Further, 'naturalistic' generalizability (Smith, 2018) was attained through accurate accounts of the course facilitator's and Peter's experiences to enable the reader to interpret the findings. A group of 'critical friends' provided alternative explanations and insights throughout course delivery and data analysis.

Results
In the results, the main focus is placed on Peter's learning trajectory as a PE department head and supervisor of a PYD programme implementation by the PE teachers of his department. Attention is also given to the facilitative role of the course facilitator as responsible for conducting Peter's PYD training. The data generated three themes, which present an evolving chronologic matrix of the dynamic interplay between goals, matching activities and progressions (or developmental sequences) of Peter's learning trajectory (see Figure 2 for chronologic matrix). The learning trajectory development is tentatively expressed by the conceptual and pedagogical configuration of PYD and attributes of the goals and matching activities set and perceived to be undertaken by Peter during the PYD programme field implementation.

Implicit and inherently self-emergent PYD: Unmediated PYD implementation
The training of Peter on PYD involved his cyclical participation in PYD-focused workshops that were interspersed with periods of field interventions where he supervised his PE teachers' implementation of the PYD programme. In the initial workshops, course facilitator's first goal was to «deconstruct' Peter's potential (over)simplified conceptualization of PYD» (Research log), strictly based on teacher craft knowledge. As matching activities, the course facilitator established links between core PYD concepts and Peter's current and past teaching experiences and emphasised intentionality and explicit teaching of PYD as core pedagogical strategies: Course facilitator: First step, understanding PYD. PYD aims at creating conditions, strategies, goals and activities in a deliberate, intentional and explicit way to develop personal and social skills. (Workshop 1); (…) You mentioned once you taught Sport Education. Make a bridge, in PYD, the pedagogical configuration of the learning context, the goals and tasks dynamics, the accountability processes, all is set to explicitly develop life skills, fairness, effort, positive leadership, responsibility. (Workshop 2) At this point in his learning trajectory, Peter conceptualised PYD as an implicit feature of enjoyable and playful PE necessary for student engagement in learning activities, as «regardless of the subject matter, PE is about having fun» (Peter, Workshop 1). Peter also conveyed a narrow understanding of the facilitative and proactive role of teachers in PYD. For example, he deemed the development of core life skills to be a by-product of participation in PE, not necessarily dependent on explicit teaching strategies. Peter: Never saw it (PYD) as a priority. Yet, even though we might not be aware of the values we're sharing with students, they are still learning them, unconsciously. (…) I'm not sharing responsibility if they are disruptive students. As soon as they prove they can be responsible, then giving them autonomy, yeah, it's a plus. (Workshop 1) As the initial goal as PE department head, Peter decided to impose on teachers the implementation of a PYD approach: There are about 40, 50 teachers. Will send an e-mail with a set of learning outcomes and strategies for developing life skills. This is to be implemented in all schools. I'll make it clear that those not adhering to the programme may not meet the department's PE goals (Workshop 1).
During a first stage of Peter's supervision of PYD field implementation, he began to realise that any successful programme implementation would require the design of a more coherently structured programme of activities: «to work in depth some PYD topics, more planning seems important» (Reflective diary). However, his discourse did not align with the actual matching activities he put in place. Peter still conveyed a superficial comprehension of PYD, featured as a set of reactive teaching behaviors instead of a deliberate plan of sequenced PYD activities: «Essentially, teachers should be managers. They need to know how to manage problems unexpectedly emerging with disruptive students.» (Reflexive diary). As core matching activities, Peter used a depersonalized and distantly monitored approach to support the programme implementation. There was no effective perception of the actual level of PYD implementation: I sent them [PE teachers] a couple of e-mails as reminders that when problems arise, they should stop and talk about positive behaviors with their students. That they try to implement the initially set strategies. Received a few e-mails back. Apparently, the proposal was welcomed, likely some teachers implemented these strategies (Reflexive diary). In a second stage of PYD implementation, the course facilitator attempted to focus on the challenges faced by Peter with the main goal of addressing specific «needsimprovement topics suggested by Peter during ongoing email exchanges» (Research log). At this point, the course facilitator scaffolded (matching activities) Peter's understanding of PYD implementation «upon examples of his own repertoire of PYD teaching practices». Second, there was also a focus placed on explicit strategies that Peter could use to best «supervise and control the process of programme implementation» (Research log). The goal was to empower PE teachers through collaborative decision making:

Emergent teaching intentionality and modelling of positive life skills The aftermath: Achievements, barriers, and insights
Course facilitator: A strategy I use to foster perseverance. A team throws a shot on goal, two points are awarded for their efforts, not only for the goal scoring. A team of lessskilled players, who try really hard, is formally valued. There is a simultaneous achievement of motor and PYD goals. (Workshop 2) (…) You can select the criterion that suits you best, ask a specific teacher to pinpoint a particularly problematic group of students, design intervention strategies together and then ask the teacher to keep ongoing records on their progress that you can access to. (Workshop 3) During field implementation, as a learning trajectory progression, Peter established different levels of programme implementation, which resulted in different degrees of PYD implementation. At the one level, in attempting to recruit «teachers that would be more naturally receptive to PYD implementation» (Reflective diary), Peter centered his main intervention in a sampling of five teachers and their classes in one school known by its large community of underserved students. Peter's matching activities included «working with the teachers more closely and through forth and back e-mail exchange, to establish together a more coherent set of PYD activities focused on life skills content (respect and perseverance development)» (Reflexive diary). During this period, «the teachers tried to intentionally incorporate in their regular lessons some of their own PYD strategies, like, extending the PYD award scoring system to dynamics of many learning tasks» (Reflexive diary). At a second level of intervention, to expand the implementation of PYD to other schools, Peter presented a «more simplified set of strategies to the rest of the teachers» (Workshop 3). In order to extend teacher adherence to PYD implementation, Peter opted to explicitly incorporate the PYD content into the structure of naturally occurring teaching moments in PE: Peter: It's key that teachers don't see PYD as a work overload. All schools have a series of 'tournaments' embedded in their annual syllabus. It was simply a matter of rechanneling those tournament focus, by explicitly instructing teachers to introduce the PYD scoring system. Emphasising effort, respect and perseverance.» (Workshop 3) However, for most teachers, «teaching PYD was an oneoff episode restricted to the tournament series» (Reflexive diary). At this point, Peter failed to effectively advocate for the overarching educational potential of PYD: I see clearly how I could integrate many PYD activities in my own teaching. Yet, I struggled to provide a more solid argument in favour of PYD when some teachers inquired me on more complex aspects of this approach. I needed a more systematized document (literature) or line of reasoning to best uphold my argument. I feel I undersold it as many of teachers pictured PYD as some set of simple managerial strategies no more sophisticated than their current teaching practices. (Reflexive diary)

The aftermath: Achievements, barriers, and insights on future institutional PYD implementation
In the final stage of the intervention, the course facilitator presented a few higher structured pedagogical frameworks for implementing PYD; namely the Teaching Personal and Social Responsibility model and an online self-directed interactive tool (i.e., Project SCORE) (research log). During the workshops, Peter learned about the main features of these resources and was encouraged through to invest time in further understanding these tools (goal).
Through the application of these tools, Peter's most relevant achievement as a PE department head was the ability to involve a greater number of schools and teachers in the systematized implementation of PYD in PE lessons. However, the intervention time (four weeks) with the cohort of schools (three underserved community schools) selected for the implementation was too short a period to develop the programme as, «we worked on respect the feelings and right of others and a few other activities about team effort and collaboration. All was on track but then the sequence stopped abruptly with the school term ending.» (Reflexive diary). As a supervisor's matching activity, Peter attempted to scaffold teachers' implementation of the programme by, «screening what strategies they were developing, and from there, through shared reflection, helped them refine the plan of action based on their own experiences and comprehension of the PYD.» (Interview).
In relation to the largest community of PE teachers, Peter continued to email them specific didactic examples of how PYD could be embedded in their daily PE practice. However, Peter highlighted his inability to effectively 'control' the coherent and systematic implementation of the programme, «they didn't want to break the arrangement we had, they like PYD, but perhaps not enough to keep on developing it by self-initiative, if this meant extra lesson planning. All in all, it was too overwhelming trying to help so many teachers.» (Interview).
A summary of the overarching insights and recommendations for future coherent and sustained PYD intervention programmes emerged from a final reflection on the overall PYD intervention experience. At a final stage of Peter's learning trajectory, he realized both the shortcomings in his mediation of PYD and «the need to operate the implementation process at a 'systemic level'» (Reflexive diary). Two major considerations, and respective goals and intended matching activities for future implementation of PYD programmes in the institution were established. First, the need to generate more effective regulation systems through embedding the implementation of PYD into the macro structure of the department's pedagogical aims, guidelines and teaching practices. Second, the need to actively engage those PE teachers in experiential learning sustained by more effective and continuous collaborative and critical reflection on their lived experiences: Peter: A more global and sustained approach would involve formally establishing PYD goals from the beginning of the school year. Work with teachers from the outset of the process as to better integrate it into their daily practices. Also, that they realize very clearly that we are paying attention to what is happening in their PE lessons. Some teachers will struggle with this change, and those will need more effective and collaborative reflection. (…) A good idea would be to run a series of short workshops with a smaller group of eight to ten teachers and listen to what they have to say. Their concerns, their limitations. What are they already doing that reflects PYD? How can we build on that to give further credibility to this philosophy? (…) This would also imply a reconfiguration of my duties and tasks as a programme leader. Simply sending teachers an email, even if providing them a handbook with a large set of PYD activities and hoping for PYD implementation won't do. (Interview).

Discussion
The purpose of the present study was to develop a comprehensive understanding of Peter's learning trajectory attempting to mediate the implementation of a PYD approach by the PE teachers of his department. This study also examined the effects of the training protocol and the strategies and processes used to facilitate Peter's learning trajectory. To our knowledge this was the first study in PYD exploring the processes used by a PE department head to train PE teachers to adhere to and implement a PYD intervention.
At the initial stage of the PYD intervention, Peter held an oversimplified and narrow conceptualization of PYD and considered the need to foster PYD implicitly. With the course facilitator's support, Peter changed his perspective on PYD and highlighted the importance of an explicit approach towards PYD for better PYD outcomes. More specifically, Peter progressed from a narrow perspective of PYD as an inherent and naturally emerging outcome of participation in PE to an understanding of PYD as a more structured programme of activities with a life skill focus (i.e., explicit approach). Several researchers (Bean et al., 2018;Hellison, 2011) have raised awareness about the benefits of an explicit approach towards PYD. As a programme supervisor, Peter also progressed from a imposition of a PYD programme to the ability to engage some PE teachers in a collaborative implementation of activities. Previous research (Cruickshank, 2017;Neves, 2019;Silins & Mulford, 2004) has alluded to the fact that school administrators need to actively engage teachers and school staff in order to generate a shared vision that includes PYD as an overarching framework. Hence, Peter engaged in concrete efforts to progressively help PE teachers foster PYD outcomes. However, the main constraints to effective implementation of the PYD programme included the limited and deficient control of the PE teachers' activities and the timeline selected for the intervention. If PE teachers are to foster a PYD mandate, PE department heads should have a broad vision about PYD, train PE teachers to use an explicit approach towards PYD and provide continuous guidance that serves the purpose of prompting PE teachers to develop reflexive routines centered around PYD. Thus, for a PYD philosophy to emerge within school organizations a top-down approach to PYD might be needed as key stakeholders (e.g., school managers, department heads) could develop explicit efforts to embed PYD within PE teachers' teaching philosophies and current practices. Considering the importance of PE in children's holistic development and quality learning environments (Ortíz, Cid, Allepuz, & Sánchez, 2019;Pueyo, Pedraz, & Alcalá, 2019) there needs to be an explicit PYD focus embedded within school organizations which requires an ecological perspective. Many PE interventions continue to use a narrow approach to teaching PYD (Martinek & Hellison, 2016) as proximal (teachers, school managers) and distal (policy) systems need to converge and include PYD as a priority. Considering the diverse ways through which children across educational systems experience PE and extracurricular activities that include physical activity, more attention needs to be paid to sustainable PYD programming. There is the need to develop PYD-focused training programs for youth and «follow-up» processes must be enriched with traning for supervisors of such programs, because the euphoria with which PYD begins may end up being diluted with no organizational support.
Although there is a strong concern to expose PE teachers to solid theoretical resources, most interventions have failed to consider the dynamic, social and interactive nature of teaching and learning and how to transform theoretical knowledge into practical and teachable processes in real school contexts (Woods, & Conderman, 2006). In the present study, in order to change Peter's conceptualization of PYD and prompt him to use explicit and structured strategies to help PE teachers learn how to foster PYD outcomes, a scaffolded intervention based on the principles of a constructivist perspective was used (Casey & MacPhail, 2018). Several researchers have alluded to the advantages of scaffolded interventions (Pol, Volman, Beishuizen, 2010). The scaffolded intervention of the present study has been proven useful to help Peter build new knowledge of PYD activities and strategies upon his past teaching experiences, which helped him provide support to PE teachers attempting to implement PYD in their lessons. This intervention included (a) concrete guidelines about how to provide experiential learning opportunities for PE teachers that may help them improve their practice, (b) a focus on Peter's needs, challenges and goals, and (c) opportunities to develop reflexive routines/skills. Hence, scaffolded PYD interventions could provide the necessary support for PYD to become a more generalized mandate in schools and increase reflection on programme design and sustainability.
Despite the scaffolded intervention conducted by the course facilitator, there were several challenges inherent to the facilitative role he has taken up. Overall, it was difficult to implement effective strategies to effectively support the role of Peter as a mediator of the implementation of PYD by his PE teachers. Namely, the deficient monitoring and scaffolding of PYD implementation by the PE teachers and the lack of timing for exposing PE teachers to PYD materials. Previous studies (Coakley, 2016;Wright et al., 2016) have referred to PYD as a challenging endeavour due to socio-cultural forces that influence stakeholders such as PE department heads to consider PYD as an unfeasible approach. These trials and tribulations faced by Peter might have also been caused by the lack of support provided by the course facilitator who failed to develop a more comprehensive set of 'matching activities' that could more thoroughly monitor and guarantee fidelity and efficiency of PYD implementation. It should be stressed, however, that developing a PYD intervention similar to the one used in this study is a very time-consuming and challenging process.
On a final note, there remains a marked necessity to develop knowledge on potential mediation strategies that can best help PE department heads provide more effective support to those PE teachers implementing PYD as a new pedagogical philosophy and practice. Furthermore, research teams and PYD programme leaders should also assess fidelity of PYD implementation more thoroughly to understand the extent to which PE department heads are effectively leading the implementation of PYD programmes. The issue of fidelity has been raised by several researchers (Escartí, Llopis-Goig, & Wright, 2018;Pozo, Pérez-Ordás, & Grao-Cruces, 2019) that have considered assessing the implementation of PYD programmes crucial for quality developmental experiences. Nevertheless, most studies have focused on the fidelity of PE teachers throughout the implementation of PYD programmes as department heads, school managers and other stakeholders may need to be considered and fidelity assessed. Such an approach may provide a more complete understanding about the extent to which programmes are indeed integrating PYD principles. Previous research has also highlighted the need to provide to PE teachers some onthe-ground supervision and effective pedagogical guidance during their implementation of PYD (Wilson, Bloom, & Harvey, 2010).

Conclusions
This study represented the first attempt to understand the dynamics of institutional implementation of a PYD programme. In particular, an examination was made of the role of a PE department head and the effects of a PYD-based intervention examined. However, there are a few design limitations to be acknowledged in this study. First, this study was conducted within a specific socio-cultural context. The reader should be careful not to assume the findings in this study might reflect a larger PYD culture present in Portugal and/or in other European school systems. Second, no systematical observation data was collected to further understand Peter's practices and PE teachers' responses, which could have increased our understanding of this learning trajectory. Finally, while there was a focus on deepening knowledge of the role of two critical elements of the process, Peter (the PE department head) and the course facilitator, the data collection protocol in this study did not allow to capture the voices of the PE teachers implementing the PYD programme.
Moving forward, future studies should include the perspectives of both PE teachers and their students as these are key social agents in any PYD endeavour made by other stakeholders. Further, future research should consider using a multiple methods approach to analyse the learning trajectories of PE department heads and other educational agents (i.e., PE teachers). Studies combining objective measures of student achievement of PYD outcomes with the analyses of the matching activities within the process (both from a teaching and a programme supervision standpoint) leading toward such effective development would be of high interest to the field. More research is also needed to understand what 'matching activities' can best facilitate the application of PYD pedagogical resources by PE department heads and create solid grounds for PYD outcomes.
In sum, the present study sheds light on the complexity of integrating PYD within the school system. On one hand, facilitators of PYD programme implementations, as the case of the course facilitator in this study, must consider the intricate nature of integrating PYD within school settings. On the other hand, PYD is dependent on social forces derived from the educational system, schools' priorities, peer pressure, parents' concerns, among other factors that influence how PE teachers teach PE. As society changes and youth developmental needs remain a priority we should have in mind that a «well-thought-out plan of action would include ensuring a collaborative framework for parents, teachers, school leadership, school district leaders, school board members, and other key stakeholders» (Gomez & Ang, 2007, p.101). This study hopefully stimulates more research within line of inquiry as PYD becomes increasingly more relevant across socio-cultural contexts.