Lifelong Learning through Teacher Design Teams for Interdisciplinary Teaching in Secondary Vocational Education: The Perspective of Different Stakeholders

Abstract

Motivating students in general subjects within secondary vocational education poses a challenge for teachers. Flanders introduced Project Integrated General Subjects (PGS), an interdisciplinary course designed to tackle this issue. However, despite its establishment, the dynamic nature of both society and the vocational student population has made it challenging for PGS teachers to meet learning objectives and to motivate their students. Teacher Design Teams (TDTs) can be a valuable tool for promoting lifelong learning amongst PGS teachers through collaborative creation of curriculum materials. To examine how TDTs can be organised for this specific interdisciplinary course, five focus groups were conducted with PGS stakeholders. The results show the need for a long-term TDT programme with regular meetings in school-based TDTs, complemented by meetings in a networked TDT. The school-based TDTs design curriculum materials and the networked TDT provides teachers support through knowledge exchange and feedback. In the school-based TDTs, an internal coach takes a prominent role, whilst an external coach is present in the networked TDT. Teachers’ autonomy and voluntary commitment, as well as the school management’s support and trust, are essential. Finally, meticulous documentation of the TDT’s progress and an online platform to share designed curriculum materials are recommended.

1. Introduction

This study endeavours to elucidate the desirable conditions of TDTs within the context of vocational education, with a particular focus on the interdisciplinary course Project Integrated General Subjects (PGS). In Flemish vocational secondary education, the general subjects (languages, mathematics, sciences and social education) are clustered in the course PGS. Upon the establishment of compulsory education until the age of 18 in the 1980s, PGS became an integral component of vocational students’ curriculum, aiming to furnish a meaningful framework for the general subjects [1]. PGS holds the potential to provide a relevant interpretation of the general subject matter by offering an integrated education through interdisciplinary teaching [2]. PGS’s emphasis on twenty-first-century skills through interdisciplinary and project-based learning can also encourage lifelong learning amongst vocational students [2, 3]. Consequently, providing general subjects in a functional and interdisciplinary manner can enhance student motivation, thereby positively influencing learning outcomes [1, 4].

Nonetheless, Creten et al. [5], Van Praag et al. [6] and Placklé [7] indicate that PGS insufficiently succeeds in motivating vocational students for general subjects. Creten et al. [5] show that vocational students perceive the subject matter of PGS as little useful for their future life, which results in a lack of student motivation. Additionally, Van Praag et al. [6] point out that heterogeneity of classes in the vocational track is also detrimental to students’ motivation. The student population is heterogeneous in terms of prior knowledge, level, interests and age [8]. Especially the differences in prior knowledge of general subjects are a challenge. Students with more prior knowledge, most of whom ended up in the vocational track after exclusion from other tracks, feel bored in PGS classes [6]. For these students, the content is too easy and often repetitive, which causes them to misbehave and disrupt classroom practices. Consequently, other students encounter difficulties in paying attention, which also reduces their motivation. Therefore, differentiated instruction is necessary for this track but frequently missing in practice [7].

PGS exhibits deficiencies not only in terms of student motivation but also regarding learning outcomes. In 2013 and 2022, the Flemish Government conducted a region-wide assessment research to examine if vocational students in the second year of the third grade met the attainment targets for the course PGS [9, 10]. The results of these assessment research studies indicate that PGS fails to achieve its objectives, as over half of the students do not meet the basic level for numeracy, reading and listening skills.¹ A follow-up investigation on the 2013 assessment research reveals that the PGS course struggles with a multitude of challenges intricately interconnected across various levels: the student level, the class and teacher level, the school level and the level of the Flemish education [8]. Consequently, numerous recommendations were formulated for the government, teacher training programmes, educational guidance services, school principals and PGS teachers. These recommendations consistently emphasise the need to prioritise the professional development of and collaboration amongst PGS teachers.

In conclusion, the advantage of the developed PGS is not yet reflected in the motivation and/or students’ learning outcomes [5, 6, 7, 8, 9, 10]. PGS teachers are key actors in providing a curriculum that motivates students and stimulates learning gains as they are expected to design teaching materials specifically for their student group [8]. Despite their good intentions, PGS teachers frequently fail to teach the course effectively [8, 11, 12]. Generally, this can be explained by the frequent lack of specific teacher training for the course as any teacher is allowed to teach PGS [12]. PGS teachers frequently acquire qualifications in specific subjects, inadvertently lacking the comprehensive knowledge necessary for PGS and experience in teaching diverse and heterogeneous vocational student groups. Because of the complexity of PGS, the course is challenging not only for beginning teachers but also for more experienced teachers, making long-term professionalisation initiatives necessary.

According to the study conducted by Sierens et al. [8], Teacher Design Teams (TDTs), described as groups of teachers collaborating to design new curriculum materials, can foster cooperative efforts amongst PGS teachers and can converge a variety of expertise to design curriculum materials tailored to students. This suggests that integrating TDTs within the context of PGS fosters a culture of lifelong learning amongst teachers, enhancing their adaptability to the dynamic landscape of vocational education and its student population. Simultaneously, leveraging this acquired expertise, teachers actively engage in designing new curriculum materials for PGS, potentially boosting student motivation and elevating learning outcomes.

2. Theoretical framework

2.1 The purpose of the interdisciplinary course project integrated general subjects

The course Project Integrated General Subjects (PGS) integrates general subjects. Through interdisciplinary teaching, PGS tries to reflect the complex and all-encompassing reality [11]. Therefore, striving for real-life and problem-based learning is crucial as it not only motivates students but also fosters equal educational opportunities [12]. Fostering this is crucial, as noted by Van Houtte [13], given that students with a lower socio-economic status or immigration background are more likely to be tracked into vocational education. This underscores the disparities present in Flemish education. Therefore, PGS’ main objective is empowering these often vulnerable vocational students to become self-reliant and resilient in society and (professional) life [1, 4, 11].

To meet this objective, project-based learning is used by teachers in PGS classrooms [11]. Project-based learning is an active and student-centred instructional approach which encourages autonomy and constructive collaboration towards a determined goal within real-world settings [14]. Additionally, PGS connects subject matter thematically to students’ daily life and interests to make subject matter functional [4].

Research by Placklé et al. [15] focuses on the course PGS to investigate if vocational students’ preferences on learning environments correspond with the beneficial conditions in the literature. Placklé et al. [15] synthesise the favourable conditions from the literature into the Model for Powerful Learning Environments in Vocational Education (PoLEVE). According to this model, the learning environment should align with the vocational students’ needs. Learning tasks should be both authentic and challenging, with coaching, assessment for learning and differentiation serving as the foundational elements for adaptive learning support. Additionally, Placklé et al. [15] argue that there is an emphasis on cultivating twenty-first-century skills, including self-regulation, problem-solving and collaboration. These prerequisites should be integrated into a positive and safe environment, where students can confidently engage in their learning process.

The learning objectives for vocational students are determined by the attainment targets. These attainment targets are established by the Flemish government. The PGS attainment targets and curricula are intentionally designed to remain quite open and flexible to realise lifelike learning, tailor-made to the students [4]. Whilst this flexibility grants teachers autonomy, it also results in vagueness and ambiguity, stemming from the multitude of potential directions they can explore whilst developing curriculum materials. Furthermore, customising curriculum materials for PGS to meet the unique needs and interests of specific student groups is essential. Consequently, modifications are often necessary to make these materials applicable to different student groups [11]. Therefore, a lot of engagement is expected from PGS teachers [4] and due to the complexity of the course and the student group, there is a high need for expertise in the course amongst PGS teachers [12]. Nevertheless, as evidenced by the 2013 assessment research [9], there exists a deficiency in the required didactic and multidisciplinary expertise amongst these teachers.

2.2 The basic principles of teacher design teams

A Teacher Design Team (TDT) can be described as ‘a group of at least two teachers, from the same or related subjects, working together regularly, with the goal to (re)design and enact (a part of) their common curriculum’ ([16], p. 215). Consequently, a TDT is a Professional Learning Community with a focus on (re)designing a curriculum [17]. This (re)designing can include various curriculum components: its scope can vary from single lessons to entire training programmes [18]. Working with TDTs is a long-term and intensive way of professionalising teachers, making it more likely to be effective [19].

According to Binkhorst et al. [17], a TDT has two main objectives: (1) The first objective is the design of new curriculum materials that are useful in classroom practice [17]. Teacher-designed curriculum materials provide a sense of ownership to the teachers and increase the effective use of these materials in class [20]; (2) The second objective is the professional development of the participating teachers [21]. By developing a new curriculum, teachers share their knowledge and skills, learn from each other and improve their classroom practice. A TDT can be organised as a school-based TDT with teachers from the same school or as a networked TDT with teachers from different schools [22]. In Handelzalts’ [16] research, school-based TDTs were used to facilitate school-wide reform, with teachers actively engaged in shaping and designing these innovations. Networked TDTs have the advantage of enhancing the quality of professional development since teachers from different schools collaborate and knowledge is shared [22]. Both objectives of a TDT contribute to the ultimate goal of TDTs: the improvement of student learning outcomes [23].

The quality of both curriculum materials and professional development is influenced by various conditions. Binkhorst et al. [17] created a conceptual framework depicting important conditions of a TDT. These conditions are divided into three stages: (1) outcome, (2) input and (3) process. The (1) outcome stage encompasses the two objectives and results of a TDT. The conceptual framework’s (2) input stage encompasses two distinct categories: individual conditions, which relate to the participating teachers, and contextual conditions, which relate to the participating school. The importance of teachers’ autonomous motivation, their positive attitude towards reform and their design and teaching experience are pointed out as individual conditions. Amongst contextual conditions, the school’s ambitions regarding the reform, teachers’ commitment to this reform and the emotional and practical support for the TDT are considered important [17]. The (3) process stage relates to elements that characterise and impact the functioning of the TDT during its active phase. Important processes are constructive team interactions, determination of a common goal and activities both inside and outside the TDT meetings. Binkhorst et al. [17] emphasise the central role of a team coach. The coach is the person who manages the processes within a TDT, without focusing on the content of the curriculum materials. Additionally, Binkhorst et al. [17] also note the practical organisation of a TDT as an important process factor. The choice for school-based or networked TDTs, the term of the programme, the group size and location, frequency and duration of the meetings all influence the quality of the professional development and the designed curriculum materials.

The successful implementation of a newly designed curriculum is more likely when it gains support, acceptance and legitimacy from the wider school team [18]. Emphasising this, Jonker et al. [18] highlight the crucial role of the TDT in actively cultivating support amongst colleagues teaching the same subjects within the department. Handelzalts [16] emphasises the crucial role of school principals as their involvement is important for the success of a TDT. The school principal must enable the organisation of a TDT and must provide support interacting with the TDT and aligning reforms within the TDT with reforms within the school.

2.3 Teacher design teams in vocational and interdisciplinary contexts

The use of TDTs in the specific context of the course PGS has not yet been investigated. Nevertheless, several studies have been conducted in similar contexts [24, 25, 26]. Research on TDTs in interdisciplinary and vocational education contexts provides interesting insights.

The PhD research of De Meester [24] examines how TDTs can be used to design new curriculum materials for integrated STEM (iSTEM) education. iSTEM stands for the integrated instruction of science, technology, engineering and mathematics. Its purpose is to demonstrate the interdisciplinarity of the subjects and to increase students’ interest and understanding of STEM. PGS and iSTEM exhibit parallels as they both prioritise an interdisciplinary approach that encompasses various subjects. The iSTEM research mainly explored important stages and pitfalls during the design process and focused on strategies and learning gains of teachers who participated in a multidisciplinary TDT. In the research of De Meester [24], each iSTEM TDT involved teachers from different disciplines and an external coach. Each TDT engaged in cross-disciplinary discussions, formulated activating challenges for students and made meaningful connections across STEM disciplines. The research highlighted the value of TDTs for teacher education and in-service training. More specifically, the teachers engaged in these TDTs expressed their appreciation for the interdisciplinary collaboration and acknowledged learning gains. Amongst the participating teachers, there was an improvement in metacognitive thinking and a positive shift in their attitude towards problem-solving [24]. However, the study also illuminated certain pitfalls reported by teachers. These were related to reverting to a discipline-specific approach and creating practical activities with limited learning opportunities.

Albashiry’s [25] doctoral research is situated in the context of Technical Vocational Education and Training (TVET) in Yemen. In many developing countries, exemplified by Yemen, there is a notable disparity between the scope of TVET programs and the demands of the labour market. As the purpose of TVET is to cultivate skilled workers to drive economic growth, this discrepancy is inherently paradoxical. This discrepancy is attributed to teachers’ inadequacies in curriculum development and a deficiency in curriculum leadership amongst academic managers like heads of departments. In this regard, the context shows similarities with PGS—the context of this study—as PGS aims to prepare students for their professional life [9]. According to Albashiry [25], teacher collaboration within design teams improves both the internal and external consistencies of the curriculum. Internal consistency relates to the coherence between different parts of the curriculum, whilst external consistency relates to the alignment of the curriculum with the labour market demands. External consistency is also stimulated by involving external stakeholders as co-designers [25]. Furthermore, Albashiry [25] shows that the professional development of department heads in systematic and collaborative learning approaches strongly supports collaborative curriculum design. This cultivates a deeper appreciation amongst department heads for a collaborative approach to curriculum design.

A case study of Placklé et al. [26] with pre-service teachers in their final year of PGS teacher education indicates the opportunities of TDTs for the course PGS. During their training, the pre-service teachers had to design curriculum materials according to the conditions of a PoLEVE and with the integration of vocational subjects in PGS [15]. To achieve this, research teams were formed with these pre-service teachers, a teacher educator, vocational subject teachers and PGS teachers [26]. The project illustrated the benefits arising from collaboration amongst diverse stakeholders in designing a curriculum. This joint effort not only entailed the collective responsibility of shaping Powerful Learning Environments in Vocational Education (PoLEVE) but also enhanced vocational students’ learning via collaboration with various stakeholders. Through dialogue, stakeholders reached a collective understanding of PoLEVE, establishing a unified perspective and terminology [2]. A shared understanding of PoLEVE is crucial for enabling its design. Moreover, the collaboration in research teams generated continuous learning for pre-service teachers, in-service teachers and teacher educators.

3. Method

3.1 Research goal and research questions

As the existing literature (e.g. [17, 23]) on TDTs shows, several conditions influence the functioning and outcomes of TDTs in education. Research (e.g. [18, 27]) shows the promising conditions for Teacher Design Teams but is often conducted within the context of higher education or ICT implementation. The research reported in this article explores promising conditions of successful TDT approaches in the context of vocational education by examining the perspectives of multiple PGS stakeholders. Consequently, the research question tackled in this article is: ‘Which conditions are desirable for the implementation of TDTs within the context of the vocational education course PGS?’

3.2 Research context

This study is conducted in Flemish vocational secondary education in the context of the course Project Integrated General Subjects (PGS). Flemish secondary education is divided into three grades, each lasting two years. In the second and third grades, students choose a field of study in one of the four tracks. Ranked according to the decreasing importance of theory and the increasing importance of practice, these four tracks are ‘general education’, ‘art education’, ‘technical education’ and ‘vocational education’. Flemish education is often referred to as a ‘cascade system’ [6]. This means that many students usually start their educational career in the general track, which has the highest social status due to the high degree of theory [28]. Over time, some students drop out and move to less theoretical and thus less valued tracks. Consequently, attending the vocational track is rarely a positive choice and often feels like a failure to the students [6]. This presented context is also reflected in the course PGS, where heterogeneous class groups differ in terms of motivation and prior knowledge.

3.3 Data collection

Five focus groups were organised with diverse PGS stakeholders: six pedagogical counsellors (focus group 1), six teacher educators (focus group 2), three education inspectors (focus group 3) and four and five teachers (focus groups 4 and 5, respectively). These stakeholders were chosen because they encounter the vocational track and PGS in daily practice. Therefore, they can advise on the conditions of TDTs for PGS. Audiovisual focus groups were organised online², offering similar data as physical focus groups [29]. The focus groups were conducted in May and June 2020 and lasted between 70 and 88 minutes. All participants agreed with the informed consent obtained in advance.

Based on the literature, four overarching components are deemed adjustable factors to consider when organising TDTs. These components are (1) organisational structure (school-based or networked TDT), (2) composition of the TDT, (3) term, frequency and duration and finally (4) guidance and support. (1) Organisational structure pertains to the formation of TDTs with teachers from the same school (school-based TDT) or teachers from different schools (networked TDT). For example, Handelzalts [16] focuses on school-based TDTs, whilst Binkhorst [17] concentrates on networked TDTs. (2) Composition of the TDT addresses which teachers or participants should be involved in a TDT. Binkhorst et al. [17] demonstrate in the integrated conceptual framework that the members of a TDT and their characteristics are crucial for the TDT outcomes. Therefore, the selection of who participates in a TDT is significant. For (3) term, frequency and duration, it was again established in the integrated conceptual framework of Binkhorst et al. [17] that the way the TDT is organised is an important consideration. Finally, (4) guidance and support were derived as the last overarching component from the literature for various reasons. Firstly, it is evident in the integrated conceptual framework of Binkhorst et al. [17] that the coach plays a crucial role in supporting the TDT. However, a broader component ‘guidance and support’ is chosen, as Handelzalts [16] also emphasises the significant role of the school principal in supporting the TDT. Additionally, Jonker et al. [18] demonstrate that support from colleagues teaching the same subjects within the department is also necessary for the functioning of the TDT.

During the focus groups, a brainstorming exercise was used as an active technique to collect data [30]. During the brainstorming exercise, a basic setup of a TDT was presented which contained the four components: ‘Two PGS teachers (composition of the TDT) from the same school (organisational structure) and a coach (guidance and support), who guides and supports, meet monthly for a full school year in a TDT (Term, frequency and duration)’. The participants received individual time to think about the desirable adjustments to enable TDTs in the context of an interdisciplinary course, exemplified by the course PGS. Afterwards, the participants shared and discussed about how they would organise TDTs within the context of the course PGS. In this process, consensus was always sought between the participants of each focus group. To ensure clarity of ideas, the focus group moderator documented each idea per component on a shared document. Before this brainstorming exercise, the participants were asked how they would define TDTs. Afterwards, schematic representations of TDTs were presented so the concept was unambiguous.

3.4 Data analysis

A qualitative research approach was adopted in this study [30]. Firstly, the recordings were transcribed verbatim to enable coding and interpretation of the data. Subsequently, an iterative coding process unfolded across three rounds. In the first round of coding, in vivo codes, in the language of the participants, for TDTs and the course PGS were drawn up. In the second round, the codes were related to each other and merged into categories. This second round led to a summary report of each focus group with a focus on the developed categories and was sent by email to the participants to obtain their feedback and agreement with the summary. Asking the participants for feedback leads to member checking and has the purpose of ascertaining whether the participants agree and whether adjustments need to be made to the summary [31]. Apart from a few additions, nobody disagreed. Finally, during the last round, patterns were searched and the focus was put on the matching and complementary elements that were raised by the different stakeholders. The perceptions of the different focus groups and consequently stakeholder groups were linked in this way. During the analysis, the four important categories derived from the literature (1. organisational structure, 2. composition, 3. term, frequency and duration, 4. guidance and support) functioned as sensitising concepts [32]. Based on the results, a TDT programme for the interdisciplinary course PGS was suggested.

4. Results

The results are presented according to the four components considered in this research. The corresponding and complementary ideas of the stakeholder groups are presented per factor: 1. organisational structure, 2. composition, 3. term, frequency and duration, 4. guidance and support. These insights lead to a recommendation for TDTs within the context of the course PGS.

4.1 Organisational structure

Teachers and teacher educators mainly emphasise the benefits of school-based TDTs. Both see advantages in organisational feasibility and stress the possibility of close cooperation. Teacher educators also emphasise the possibility of designing curriculum materials for one’s students. Pedagogical counsellors stress the usefulness of networked TDTs in which expertise is merged and schools can reinforce each other. Education inspectors have no preference and state that TDTs must meet the needs of the school and teachers (e.g. experienced or not).

Despite their initially stated preferences, the stakeholders acknowledge and appreciate the inherent value of more alternative organisational structures. Teachers recognise that networked TDTs facilitate the convergence of teachers from diverse backgrounds, enabling the sharing of varied knowledge and experiences. Concurrently, teacher educators admit that teachers from different schools can serve as critical friends. The concept of critical friends pertains to peers engaging in the provision of feedback, guidance and constructive critique to enhance one another’s curriculum materials. External teachers possess a distinct advantage in critically evaluating developed materials, thereby offering new perspectives. Pedagogical counsellors attribute value to school-based TDTs due to a more facile organisation, eliminating the necessity for substitute arrangements.

Each stakeholder group acknowledges the possibility of combining both TDTs to unite the best elements in a TDT programme. Education inspectors indicate the usefulness of complementing a networked TDT with school-based TDTs, so the information of the networked TDT would reach the schools. The teachers and teacher educators elaborate on this as the design of curriculum materials can take place in school-based TDTs, whilst knowledge and feedback on the designed materials can be shared in a networked TDT. To put it differently, the integration of school-based TDTs and a networked TDT offers the opportunity to design custom curriculum materials for students within the school-based TDT whilst receiving external knowledge and feedback via the networked TDT.

4.2 Composition

All stakeholders state that PGS teachers across grades and fields of study can join the school-based TDTs. This approach fosters a cohesive whole-school strategy for PGS, enabling continuous mutual learning amongst teachers. Teacher educators believe that a large school with many teachers is required to organise several school-based TDTs, in which communication is key. They propose the composition of several school-based TDTs by grade, whilst teachers indicate a division based on fields of study.

According to education inspectors, the participation of teachers in a TDT programme should be voluntary. If only a part of the PGS department participates in the TDT programme, communication between the school-based TDT and the other members becomes important. After all, the designed curriculum materials of the school-based TDT must be introduced school-wide for all PGS lessons. In addition, teachers also believe that participation should be guided by the motivation of the teacher. They should be allowed to choose for themselves with whom they form the school-based TDT. The education inspectors indicate that roles and tasks can be assigned based on everyone’s abilities and expertise. Finally, teacher educators point out the practical feasibility of meetings. Therefore, a school-based TDT should be limited to ten teachers.

Besides the involvement of PGS teachers within the TDTs, the inclusion of other participants may be needed. The education inspectors indicate that the requirement for such participation depends on the unique contextual factors within schools. A shortage of certain expertise can be compensated by collaboration with other departments in school-based TDTs or experts in networked TDTs. The participation of vocational teachers in school-based TDTs is also suggested by the teachers, teacher educators and pedagogical counsellors. As such, congruence between PGS and the practical subjects is achieved and authentic learning environments are designed. Pedagogical counsellors, however, raise concerns about the inherent motivation of these teachers, as they perceive less direct added value for their own vocational subjects. Therefore, their participation should not be permanent. The pedagogical counsellors recommend the composition of a networked TDT based on the expertise of the participating teachers, where teachers can complement each other’s expertise. If a networked TDT is composed of teachers from school-based TDTs, this complementary composition is not guaranteed to be possible. The teachers see the benefit of the participation of one or two teachers from different school-based TDTs. Didactic or subject matter experts can respond to the shortage of certain expertise during these meetings in a networked TDT.

Finally, all stakeholders highlight a notable turnover amongst PGS teachers. Consequently, a robust emphasis on the substitutability of teachers within the TDTs becomes imperative as new teachers will often join the team. To achieve this substitutability, prioritising the sustainability of the TDT programme is essential. Education inspectors advocate a structured approach that delineates clear intermediate objectives, enabling new teachers to easily comprehend and align with these targets. Teacher educators underscore the importance of documenting progress to facilitate the transmission of accomplished work to new teachers in the TDT.

4.3 Term, frequency and duration

All stakeholders state that TDTs should meet regularly and for several consecutive years. The education inspectors indicate that school-based TDTs should meet at least monthly. Teachers also mention the need to meet monthly, but stress that they want to decide autonomously when and for how long they meet. Teacher educators agree that meetings should not be dictated by the school principal, but initiated by the participating teachers themselves. Depending on the intermediate objectives of a school-based TDT, a meeting can be shorter or longer.

Teachers recommend meetings of the networked TDT two to four times a school year. Long-distance travel and difficult substitutions can be obstacle, so pedagogical counsellors propose a combination of physical and online meetings. Pedagogical counsellors emphasise the importance of alternating physical meetings with online meetings. Teachers suggest that a physical meeting should take at least half a day, whilst an online meeting can be much shorter.

4.4 Guidance and support

The questioned stakeholders consider two tasks for the coaches. The coach should (1) facilitate the process during the TDT meetings. Pedagogical counsellors suggest that the coach must ensure the teachers in the TDTs have a clear vision regarding the goals of the TDT. Consequently, articulating distinct and specific goals for each meeting becomes imperative. The other stakeholders agree that the coach should facilitate team interactions and monitor the structure by setting clear intermediate goals. All stakeholders perceive this function of the process coach as most essential. Consequently, it is crucial that the coach receives thorough training to fulfil this role. The coach may not only facilitate the process but also (2) offer substantive guidance, offering pertinent and valuable content advice. Pedagogical counsellors consider it as an added value, and teacher educators indicate that depending on the experience and expertise of the teachers, substantive guidance is needed. According to teachers and teacher educators, external experts can bring new insights and knowledge useful for the design of curriculum materials. The education inspectors state that these two tasks can be fulfilled by one coach, but they note that this is mostly done by several people. In a networked TDT, a permanent process coach and the occasional presence of subject matter or didactic experts can realise this.

In the case of school-based TDTs, teachers advocate an internal coach, which is a participating teacher. Teachers consider an external coach as an obstruction of their autonomy and flexibility, concerned that it might curtail their ability to independently arrange meetings and manage their own schedules. The education inspectors state that the coach must be someone the PGS teachers feel comfortable with as they must collaborate closely. An internal coach is the optimal choice, given their frequent presence amongst team members at school and their familiarity with the school’s culture. According to the teachers, the internal coach is preferably (one of) the teacher(s) who also participate(s) in the networked TDT.

For a networked TDT, an external coach seems to be useful. All stakeholders believe that the external coach does not necessarily have to be an expert in the course PGS, but basic knowledge of the course and the vocational students is necessary. Depending on the participating teachers and their need for expertise, the networked TDT can be assisted by alternating didactic and subject matter experts. The coach facilitates the process of the networked TDT, whilst external experts contribute valuable content knowledge useful for designing curriculum materials within the school-based TDTs.

All stakeholders stress the importance of support from the school principal. Without the interest, support and cooperation of the school principal, the success of a TDT programme is almost impossible. The teachers believe that sincere interest in and belief in the course PGS from school principals have strong motivating effects. Teacher educators emphasise that school principals must acknowledge the time teachers invest and must provide the necessary replacements in the case of physically networked TDTs. Teacher educators and teachers believe that school principals should schedule time for meetings of the school-based TDT. In addition, teacher educators and pedagogical counsellors also demand material support. School principals should provide this by investing in course materials and equipment for the PGS classroom. Pedagogical counsellors consider giving a mandate, wherein a teacher is allocated specific responsibility and authority to execute designated tasks, to an internal coach. This mandate functions as a recognition of the importance of the TDT programme.

Finally, the teachers emphasise the need for an online platform on which school-based TDTs can share designed curriculum materials. This online platform, complementing the networked TDT meetings, operates as a tool through which the school-based TDTs mutually foster support, inspiration and motivation. By facilitating the exchange of designed curriculum materials, this platform can foster an environment conducive to collaborative learning and the interchange of innovative pedagogical approaches amongst teachers.

5. Discussion and conclusion

Interdisciplinary teaching in vocational secondary education presents numerous challenges for teachers as the integration of diverse disciplines requires teachers to navigate the complexities of integrating various knowledge and skills, fostering a cohesive and meaningful learning environment [33]. Additionally, vocational secondary education frequently presents a demanding setting for teachers characterised by a heterogeneous student group, encompassing students with varying levels of motivation and prior knowledge [6]. Consequently, this article assumes that the course Project Integrated General Subjects (PGS) in Flemish vocational secondary education, which involves an integrated approach to general subjects, poses a challenge for all teachers. Teacher Design Teams have the potential to promote lifelong learning amongst PGS teachers, thereby facilitating the provision of high-quality general education for vocational students through the collaborative design of interdisciplinary curriculum materials [8, 17].

The central research question in this article is: ‘Which conditions are desirable for the implementation of TDTs within the context of the vocational education course PGS?’. This research question was examined by the conduction of five focus groups with multiple PGS stakeholders (pedagogical counsellors, teacher educators, education inspectors and teachers). During the focus groups, the stakeholders brainstormed on how TDTs should be organised with a focus on four components: 1. Organisational structure, 2. Composition, 3. Term, frequency and duration and finally, 4. Guidance and support. This qualitative research contributes to the existing literature about TDTs as it explores desirable conditions for each component of TDTs in the context of an interdisciplinary course in vocational education amongst different stakeholders.

The results recognise the usefulness of both school-based TDTs and networked TDTs. During at least monthly school-based TDTs, materials can be designed customised for one’s students. An additional networked TDT ensures the exchange of information across schools and the provision of knowledge and theoretical frameworks by experts. The composition of school-based TDTs depends on the size of the school and the voluntary participation and commitment of PGS teachers. The school-based TDT should inform and involve the PGS department. Depending on the expertise of the involved PGS teachers, it might be beneficial to occasionally engage other subject teachers to supplement any potential knowledge gaps amongst the PGS teachers. Due to the nature of the course PGS, this also applies to vocational teachers. In a school-based TDT, one PGS teacher is trained as an internal coach to supervise the TDT to maintain autonomy and close cooperation within the team. Given the frequent turnover of PGS teachers within secondary schools, maintaining sustainability in a long-term TDT programme is crucial. Thorough documentation of the TDT’s progress becomes imperative to guarantee continuity during transitions amongst participating teachers. Additionally, four times a school year meeting in a networked TDT can be organised with one or two participants from the school-based TDTs. In this way, schools enrich each other with external knowledge and feedback on the designed curriculum materials. A combination of physical and online meetings can reduce travelling time for the participating teachers. An external process coach is assigned to the networked TDT. Subject matter and didactic experts provide additional support (during some meetings) according to the needs of the permanent members of the team. Support, confidence and resources from the school principal are important for the TDT programme to succeed. Finally, an online platform to share designed material from the school-based TDTs could be of great support.

This research offers three innovative insights. Firstly, the advantages of school-based TDTs and networked TDTs are united in one TDT programme in which collaboration within the same school but also across schools occurs. Literature (e.g. [16, 17, 21, 22, 34]) frequently focuses on school-based or networked TDTs and highlights the associated benefits of one organisational structure of TDTs. The findings of this research recognise the advantage of networked TDTs, attributed to their potential to enhance teachers’ professional development by leveraging external knowledge sources as shown by Binkhorst et al. [22], as well as the advantage of school-based TDTs in facilitating school-wide reforms as shown by Handelzalts [16]. The research results in this article emphasise the imperative of conscientiously tailoring curriculum materials to suit the specific student group, particularly within the context of secondary vocational education. Enabling this customisation is achievable through the collaborative design of curriculum materials by teachers within the same school, more specific by school-based TDTs. A networked TDT facilitates the acquisition of knowledge across different schools and thus promotes the design process in school-based TDTs. Ultimately, the combination of both organisational structures can ensure the integration of the benefits both TDTs offer. For example, curriculum materials can be designed specifically for the school’s student population whilst integrating knowledge from outside the school. Secondly, the important function of a coach, proposed as mostly an expert in their field in the integrated conceptual framework of Binkhorst et al. [17], is further elaborated. The findings in this article propose an internal coach, which is a participating teacher, in the school-based TDTs allowing the team to work autonomously. An internal coach monitors the processes and provides content. This combination requires thorough training. Finally, an important consideration is made regarding the members of the TDTs in this article. Because of the high turnover of PGS teachers, it is recommended to think about the substitutability of the team members to ensure the sustainability of the team. Literature about TDTs often assumes a fixed team collaborating for a long time. However, it is crucial for TDTs in any context to consider the implications when a team member is replaced. In doing so, the progress of the TDT can be preserved. Setting well-defined goals with explicit milestones and recording progress in detail can make it possible for new members to function in the TDT.

Based on the results of this research, a TDT programme can be realised in different secondary schools to be examined. The findings can lead to adjustments in the TDT programme after which it can be reimplemented and re-examined in the schools. However, the results of this research also contribute on a practical level. Although this research focuses on the specific context of the course PGS, the insights can be transferred to TDTs for other (new) interdisciplinary or vocational education courses. The findings offer valuable insights to secondary schools when introducing TDTs within similar settings.