Boundary crossing in Teacher Education

1 School of Education, University of Aberdeen, UK, lecturer stephanie.thomson@abdn.ac.uk 2 School of Education, University of Aberdeen, UK, senior lecturer s.cornelius@abdn.ac.uk 3 Eötvös Lorand University Faculty of Education and Psychology Institute of Education, associate professor kopp.erika@ppk.elte.hu 4 Platform Opleiding, Onderwijs en Organisatie BV (PLATO), Leiden University, the Netherlands, director laker@plato.leidenuniv.nl


Introduction
Thee Covid-19 pandemic has had great societal impact. During local and national lockdowns across the world families were asked to stay at home. Many parents combined working at home with a new role as home-teachers as schools turned their programmes into various forms of digital education (Reimers & Schleicher, 2020). School leaders and teachers may have, at fi rst, perceived this as merely a change of methods, but soon many other consequences emerged (Cleland et al., 2020). For example, infrastructure proved to be insufficcient in many households; not all parents were competent or willing teachers at home, and some groups of children did not get sufficcient input to acquire mother tongue language skills. Staying at home also had an impact on family relationships, sometimes even leading to confluicts. Theese wider impacts illustrate how problems that are, at fi rst glance, interpreted as things to be solved in and by schools, school leaders, and teachers, ofthen require the involvement and commitment of a wider circle of professionals and other stakeholders. Theey also illustrate the need to cross boundaries to address the issues involved: boundaries between home and school, social and other support services, educators, teachers and parents. When professionals succeed in effeective collaboration and in mutual professional learning through boundary crossing, they become more effeective as individuals, as teams, and as organisations. Not only can professionals and the parents involved benefi t from boundary crossing; so too can children who will experience education which is more coordinated, fluexible and responsive to their needs.
Theis paper explores boundary crossing and how it can be useful in the professional learning of teachers. We suggest that many educational problems, like the challenges created by COVID-19 but even some that seem more straightforward, are actually wicked problems (Veltman et al., 2019) where the observed behaviour in school is only one part of a more complex and interconnected series of issues. Wicked problems in education typically require the collaborative effeort of a range of people including educators, other professionals, parents and the wider educational community (for example, academic researchers). We start by exploring a wicked problem (presented as a vignett e) identifi ed by the ERASMUS+ project PROMISE (Promoting Inclusion in Society through Education). We then show what boundary crossing is and how it can be a useful approach to tackling wicked problems in education. We then draw on several successful examples of boundary crossing in practice to show that there is not one standard method for this and how other people and processes can help. Finally, we return to the example of the wicked problem and suggest some ways this could be addressed, informed by a boundary crossing approach.We conclude with suggestions for the development of competencies for boundary crossing that could be adopted by teacher educators to equip future educators with skills for professional learning throughout their careers.

Wicked educational problems -a vignett e example
Thee ERASMUS+ project PROMISE (Promoting Inclusion in Society through Education) has gathered and explored the use of professional dilemmas as resources for professional learning. Working with educators across sectors from primary to vocational education, the project has collected examples of dilemmas faced by trainee and experienced educators and managers to explore the range of issues faced as a result of societal changes and increasing diversity across Europe (see Kools in this volume and Beaton et al., 2021). Thee dilemmas collected have been presented as a series of vignett es, and made available as professional learning resources via the project website (promise-eu.net). Vignett es have previously been used in educational research to analyse situations and support dialogues to derive insights and views in order to build an understanding of the dynamics of the practices described. Evidence suggests that these dialogues contributed to the professional development of the analysts, so what started as an analytical tool has also proved to be a valuable tool for teachers' professional development (Angelides & Gibbs, 2006). Thee PROMISE project aims to capitalise on the value of vignett es as a resource to support individual and collaborative professional learning for teachers across sectors.
Each PROMISE vignett e can be regarded as a short story without an ending. Theey have been developed by teachers and teacher educators and each one provides an accessible, rich and challenging description of teaching practice. Theey present an issue or challenge for which there is no right answer or obvious solution. Some information about context is provided within each vignett e, along with details of some of the choices and issues that a teacher or other educator facing the scenario may fi nd themselves grappling with. Some include questions which refer to possible ways in which to develop professionally in order to acquire the competencies needed to tackle the problem; others refer to the boundaries one might cross in order to involve others together with whom the problem/ dilemma may be more easily solvable, or with whom competencies may be shared and exchanged to bring solutions closer. By asking such questions the process of analysis of the vignett e as well as the search for opportunities for boundary crossing and mutual learning are promoted.
Thee PROMISE vignett es are intended to be fluexible resources for professional learning with which people can identify and to which they can bring their own perspectives in discussions in which solutions may be found (Jefferies et al., 2005). A PROMISE vignett e is included in full below as an illustration of the type of wicked problems faced in practice: "I am a teacher in special education. Our school offeers education to pupils from 12-18, who have a low IQ (60-80). It is not so much about teaching them subjects, but helpingS them to fi nd their way in society, maybe fi nd a job. Thee pupils ofthen have a low socio-economic background, broken families and other problems. Many of them are illiterate (and so are their parents). Due to the Covid-19 outbreak in March 2020, all schools needed to close. Theis was a challenge for all teachers, but it caused severe problems for our target group. Other teachers switched to online lessons, but this is no option for my pupils. Many of them do not have access to a laptop, tablet or computer and IF they do, due to their illiteracy, it is very difficcult for them to understand the instructions to participate in online teaching sessions. For these children, it is also difficcult to work individually on tasks. I can only use the telephone and short messages to get in touch with them. I have to be very creative to fi nd ways to reach and teach them. Thee problem I encounter is that I am worried about my pupils, I want to be in contact with them, I want to help them. School used to be a safe environment for them, where they could learn and develop. I am worried about their situation, their development. " (promise-eu.net Vignett e no. 12) Theis vignett e articulates clearly that the teacher is worried about the children they teach and wants to help them with their learning during the pandemicsomething with which many educators will identify. Thee closure of schools was a challenge for all teachers, but it caused severe problems for students with special needs and their educators. Remote learning is clearly difficcult for this group, both for practical reasons around access to devices and because of the individual needs of students.
Thee vignett e reveals that being able to help is further complicated by the setting that the teacher works in: 'special education' for secondary-age children.
Theere is no information about the location of the school but in most European education systems this means a school, classroom or unit that is separate from the corresponding 'mainstream' sett ing. Thee teacher hints at the kind of curriculum on offeer in this sett ing and it is possibly one that is quite restricted and focussed on 'life skills'. Thee discussion of IQ and of the curriculum suggest that they have a particular understanding of the purposes of special education. Addi-tionally, the teacher notes that the children and young people in the sett ing experience other social disadvantages such as poverty and disrupted family situations, and typically have parents with low education levels. Thee elements of context that the teacher has chosen to highlight are the features that they consider to be the most important to the problem they are facing. Thee use of language is also indicative of context and may refluect local or national preoccupations or policy priorities.
Theis vignett e provides an example of a wicked problem, something not easily solvable and not by this teacher alone. It is a situation in which parents play a part, in which technology plays a part, in which other professionals may be involved as well. For this problem to be addressed boundaries must be crossed. Theese boundaries are between professions, roles and contexts. Acknowledging these boundaries and adopting a boundary crossing approach may provide a way to explore and possibly address the problem and contribute to the further (professional) development of those involved.

A brief introduction to boundary crossing
In the vignett e above the emphasis is on one teacher and the learning and support they provide for their students. Boundary crossing is, however, relevant and powerful at various levels: for students, student teachers, teachers, teacher educators, school leaders and other professionals involved in education or related fi elds of work. Boundary crossing has been promoted in classroom teaching and learning but it is also applied in teacher professional development (Akkerman & Bruining, 2016). It has also been used as a framework from which to evaluate schools as organisations, to analyse to what extent schools offeer learning environments promoting boundary crossing to enrich learning, and to establish inclusion and enhance the mutual understanding needed for that (Gerdes et al., 2020). Theose who cross boundaries will cross and return, share and co-operate and when the process is facilitated well they will give and take, share and refluect, benefi t mutually and eventually transform. In this article we focus primarily on boundary crossing in teacher education, reviewing underlying principles below and then applying these to examples.
Theere has been long-standing interest in the learning potential of boundaries or borders in education (see, for example, the work of Giroux, 1998Giroux, , 1991Giroux, , 1992Engeström et al, 1995or Akkerman & Bakker, 2011. Underlying this interest is the belief that diffeerence creates an opportunity for learning and should therefore be considered positively rather than as a problem to be overcome. In the case of the diverse classrooms considered by Giroux (1992) for example, the diffeerence in cultural background between students could be considered a resource for learning rather than a barrier to it (see also the idea of 'funds of knowledge' proposed by Moll & González, 2004).
Boundary crossing draws on Cultural Historical Activity Theeory (CHAT) to explain how learning occurs at a boundary and the ways in which boundary crossing (and any att endant learning) can be mediated by key individuals (brokers) and artefacts (boundary objects). Boundary crossing situations are typically characterised by information-sharing across a boundary that may be geographic, cultural or professional (Akkerman & Bakker, 2011). Theough they may occur spontaneously, the facilitation of such situations usually requires a 'boundary object'. Boundary objects can include events or activities (where diffeerent people are brought together with a shared objective), resources (which can stimulate engagement of diffeerent people across a boundary) or sometimes actors (who use their insight from both sides of a boundary to make the path across more navigable for others).
Boundaries create the potential for learning but do not guarantee that learning will happen nor, as Akkerman and Bakker (2011) suggest, that the learning taking place in diffeerent boundary crossing scenarios is the same in nature or degree. Theey identify four learning mechanisms that can be triggered by a boundary crossing scenario (afther Akkerman & Bakker, 2011): 1. Identifi cation: the process of understanding the features of the diffeerent contexts separated by the boundary 2. Coordination: the process of integrating potentially diffeerent ways of working across a boundary 3. Refluection: the process of re-examining one's own practices in light of exposure to something diffeerent 4. Transformation: the process of changing one's own practices in light of exposure to something diffeerent. Akkerman and Bruining (2016) note that these mechanisms should not be considered hierarchical nor should some of them be considered preferable or bett er than others. Instead, the context will determine what kind of learning is most useful and appropriate. In a study of a boundary crossing activity for trainee vo-cational educators, for example, Cornelius and Stevenson (2019) found evidence that some of these mechanisms were experienced for most participants and some participants engaged in multiple forms of learning. However, other participants did not show evidence of any of the forms of learning. Theis reminds us that crossing a boundary alone does not guarantee that learning will occur.
Teacher educators wishing to harness the potential of boundary crossing for learning need to think carefully about the design and structure of boundary objects and who brokers are. A particular consideration is that boundary objects should stimulate productive dialogue so that identifi cation, collaboration, refluection and/or transformation is possible. Thee PROMISE vignett es are designed to act as boundary objects and, along with associated tools and activities, to encourage productive and refluective dialogue (see promise-eu.net Professional Learning Tools). Theese can be used by teacher educators (acting as brokers) to facilitate boundary crossing experiences. In the next section, we explore other examples of boundary crossing in education and analyse their features before returning to the example vignett e.

Boundary crossing in educational contexts
Five examples of boundary crossing have been selected to illustrate the breadth of application of the concept in education. Theese fi ve examples, all from European projects, are summarised in the table below, with more details provided in Appendix 1. Common themes and emerging issues are summarised to highlight some of the features and challenges of a boundary crossing approach in education.  Thee examples show boundary crossing occuring at various levels and in many ways. It occurs when students meet and talk; it happens when teachers cooperate. Boundaries are crossed when more subjects are included, when students of diffeerent backgrounds share thoughts, and when parents or members of the local community are made part of a (mutual) learning trajectory. In the examples in Table  1, we see teachers, other educators, ICT staffe, heritage staffe, entrepreneurs, peers from abroad all involved in boundary crossing -sometimes acting as brokers and other times becoming the benefi ciaries of boundary crossing.
Some of the examples in Table 1 address the learning of teachers and teacher trainees through international collaboration (Examples 1,2,3), whilst others are aimed at student learning (4,5). Thee majority are grounded within a single education sector, but Example 2 spans sectors (further education, higher education and community learning and development). Thee cross-sectoral approach allowed participants to make meaningful contributions to discussions free of organisational hierarchies, expectations and restrictions. Example 5 also goes beyond a single sector and adopted an interprofessional approach, drawing together teachers, educational scientists and museum staffe to develop new ideas for heritage interpretation.
All of the examples reveal that boundary crossing by teachers and trainee teachers results in problem solving and professional learning. Example 2, for instance, provided solutions to local problems through consideration of alternative perspectives. Example 5 shows that museum staffe and teachers developed themselves and each other through teaching history, experiencing history and relating it to current events. Example 3 helped student teachers begin to bett er understand how diffeerent participants locate themselves within educational communities. Theis particular example draws on both boundary crossing and inside-outside theory (Relph 1976) as underlying frameworks.
Where student learning is the aim of boundary crossing, there is evidence from these examples of authentic and expansive experiences providing learning outside classroom walls and in new sett ings. Students have been challenged to deal with diversity and interact with wider communities of professionals to develop new competencies. Example 4 engaged learners with wider communities to develop entrepreneurial competencies and Example 5 involved museum staffe and supported the development of lifelong learning competencies. Akkerman and Bakker (2011) suggest that a boundary is a 'sociocultural diffeerence leading to discontinuity in action or interaction ' (p. 133). Thee examples in Table 1 identify several relevant sociocultural boundaries (including cultural, geographical, disciplinary, role and sector boundaries). Technology is an additional boundary noted in Example 1. In this example, participants were required to navigate technological diffeerences to identify technology(ies) they could use to support communication with peers from another country. Pedagogy is also specifi cally noted as a boundary in Examples 1 and 3. Whilst diffeerences in pedagogical approach might be regarded as a type of sociocultural boundary (see for instance discussions of signature pedagogies by Shulman, 2005), it could be argued that articulation of this diffeerence highlights the need for common understandings of curricular issues and practice in diffeerent contexts to support teacher professional learning through boundary crossing.
Thee process of facilitating boundary crossing is a delicate matt er in which, in a balance between trust and curiosity, learners feel tempted to cross boundaries. Whilst educators are brokers in all of the examples in Table 1, self-brokering is a feature of Examples 2 and 3. Wenger (1998) suggests that brokers play a complex role, involving translation, coordination and alignment between perspectives. Where self-brokering is a feature, participants were able to draw on their own experiences to support boundary crossing and these experiences were clearly valued as opportunities to facilitate communication and shared understanding. Such an approach may encourage autonomy and self-direction, but perhaps risks distraction from the purpose of a carefully defi ned task. However, self-brokering seems appropriate in the context of independent professional learning (Example 2) and the development of future teachers (Example 3) because it allows participants to develop skills and competencies for future boundary crossing experiences.
A wide variety of boundary objects are identifi ed in the examples including physical objects -such as the city, photographs and sketchbooks (Examples 3 and 5); processes, activity instructions and assignments (Examples 1 and 4); events such as meetings (Example 2). Boundary objects can also be ideas and concepts which support boundary crossing, such as inclusive education, entrepreneurship or lifelong learning. Whilst conceptual objects are not articulated in the examples it can be assumed that these also play a role in supporting shared thinking, al -though the meaning of such objects may require some unpacking to ensure that these are consistent across boundaries.
Thee examples in the table also indicate that boundary crossing may be challenging. In Example 1, problems were primarily logistical in nature, such as fi nding concurrent space and time within two professionally accredited programmes to allow collaboration to take place. Theis example also revealed the need to secure commitment to the boundary crossing process and to support and encourage communication and reciprocity between participants. Some participants cited time as a barrier to engagement and others reported delays and problems making and sustaining contact with partners. Maintaining effeective communication across boundaries, specifi cally vocational and technological boundaries, was challenging and even insurmountable for some participants. In Example 4, it appeared to be more difficcult to promote entrepreneurship among teachers than among students. Teachers were also reluctant (at fi rst) to allow students the freedom to invent things, try things out; or be in touch with clients. Theis may have been a barrier to the initial development of the entrepreneurial competencies that the project was aiming for. Nevertheless, the project made a diffeerence and students involved felt taken more seriously than ever before.

Discussion
Thee examples above show the central features of successful instances of boundary crossing and demonstrate that the crossing of diffeerent types of boundaries may require diffeerent kinds of boundary objects and brokers. Clearly, this kind of learning can have powerful effeects -such as the transformation of practice -but how can we, as educators, instigate or support this kind of learning? In this section, we return to the example of a practice dilemma, or wicked problem, from earlier in the paper and use the headings from Table 1 to structure a discussion of the problem and some possible ways forward.

Boundaries
In the vignett e, several boundaries can be identifi ed. Firstly, a boundary exists within the school between diffeerent experience levels of educators working there. Theere are likely other teachers in the same sett ing experiencing similar issues. Thee teacher indicated that they are an experienced teacher. Less experienced colleagues may have innovative ideas or diffeerent ways of thinking about practice is-sues. Another boundary exists between diffeerent professional domains. Thee young people in the school may have other professionals that routinely work with them such as social workers, medical staffe or IT staffe. Thee school or the education authority may, for example, employ dedicated IT personnel who could provide insight and expertise into the technical aspects of learning remotely.
Another important boundary exists between school and home. Thee Covid-19 pandemic has forced education to take place at home when it would ordinarily take place at school. Thee vignett e indicates that some parents face additional challenges which may make it hard for them to support learning. However, parents are an important source of information about their own children and can provide insight into what their child enjoys, fi nds difficcult or frustrating and their wider emotional reaction to the huge changes that Covid-19 has caused.
Finally, there are cultural boundaries in the vignett e. We don't know the location of the teacher but undoubtedly there will be diffeerences in how remote learning in special education contexts is being organised in diffeerent countries around the world. Thee potential value of Covid-19 as a learning moment is that the effects are being experienced globally albeit tempered by existing structural features of educational sett ings (and wider social policy) and by governmental responses. Theis sort of information can be accessed through internet resources that link practitioners together (such as resource-based websites and discussion forums) and also through academic literature. Theere is an additional cultural boundary between those like the teacher, who has a particular way of understanding his/her situation, and others who would understand it diffeerently. Earlier, we noted that the teacher mentions several contextual factors. Theis indicates that they think these are pertinent for understanding the problem and exposes some of their assumptions about practice, the learners and the sett ing. Not all other people, including other educators, will see the situation in the same way and sometimes it can be helpful to 'disrupt' these understandings of the status quo (Armstrong, 2017).
Thee vignett e shows how boundaries have been destabilised due to Covid-19. Previous lines of demarcation between practices have become uncertain and there is an opportunity for questioning of identities and practices across boundaries (Akkermann and Bakker 2011) to support professional learning.

Boundary objects
Models of boundary crossing suggest that catalysts need to be present that make people cross boundaries. Theese should provide room for action, and a perspective of autonomy. Apart from triggering action and refluection, it is important that learners experience a kind of belongingness, as a sense of being in a process together (Deci & Ryan 1985).
In the vignett e, there are several possible boundary objects. Meetings between groups of teachers and/or other professionals may serve as boundary objects and as could documents associated with those meetings such as meeting papers, curriculum outlines and lesson plans. For some of these boundaries, the extent of the common ground shared by those on either side may be considerable (e.g. in the case of teachers in the same school) but, for others, there may be litt le common ground (e.g. between parents and teachers). Thee boundary objects chosen should refluect this and sometimes co-constructing a boundary object can be a useful exercise to surface assumptions and create a productive way forward. In the case of the home/school boundary during the Covid-19 pandemic (as in the vignett e), a co-constructed learning plan which parents and educators have developed may help to provide clarity on the aims of the educator and any limitations introduced by learning in the home environment (e.g. when activities are completed). To facilitate crossing a cultural boundary, resources such as websites, books or articles or activities associated with formal professional learning such as seminars, or assignment tasks could fulfi l this role. Table 1 shows that some boundary crossing is self-brokered by individuals on either side of the boundary. In the vignett e, self-brokering could work well to cross the boundaries within the school, between professional areas and between home and school. However, this requires a degree of knowledge of who is on the other side of the boundary and willingness on the part of those on either side of the boundary to collaborate on solving problems together. Theis self-brokered boundary crossing is perhaps most likely to happen when there is some existing relationship between those on either side of the boundary in question -perhaps through longstanding professional relationships. Thee move to widespread remote working has removed the informal gatherings between practitioners that were commonplace prior to Covid-19 in stafferooms or workrooms (Harris, 2020). Theese are places where practitioners may have previously raised their 'wicked prob-lems' for wider discussion and self-brokering may help to facilitate this important communication using other methods.

Brokers
For the cultural boundaries in the vignett e, several people could act as brokers. Crossing a cultural boundary can be self-brokered too but relies on existing networks, and there may be few people in the teacher's existing networks who can provide insight from a diffeerent cultural perspective. School leaders may have access to wider networks, but they too, may lack access to those who can provide insight from across a cultural boundary. Theose involved in organising provision for a city or country may be able to broker this type of boundary crossing more successfully. Such professionals are ofthen involved in strategic decisions about education and expected to draw on a wide range of evidence from other contexts. Theey may also have responsibility for organising programmes of training or professional development. By disseminating their work in a writt en form, authors of professional or academic publications can also act as brokers for the cultural boundary.
Who the most appropriate brokers are is heavily dependent on the situation. For all of these boundaries, boundary crossing could be self-brokered if existing relationships can be productively drawn on. In other instances, brokering is about creating links between those who are not ordinarily in contact -usually by using the existing networks of the broker or by drawing on power affeorded to them in their role.
Thee vignett e is an example of a wicked problem with no obvious solution. Thee discussion above considers how this problem might be framed as a boundary crossing opportunity to develop thinking, understand diffeerent perspectives and work with others towards possible solutions. Experienced professionals will have examples of wicked problems from their own experiences to draw on and explore but, for new and trainee educators, examples such as those provided amongst the PROMISE vignett es will help them explore practice dilemmas and develop confi dence and competence for their own contexts.

Conclusion: developing competencies for boundary crossing
Theis paper explores boundary crossing as a pedagogic strategy in a range of contexts. Thee examples discussed in Table 1 reveal that effeective learning through boundary crossing requires buy in and commitment to the process, clear and open communication, a commitment to reciprocity, willingness to deal with un-certainty and alternative perspectives, and the ability to refluect individually and collectively. Theese requirements can be supported by an effeective broker, but need to become embedded as 'competencies' in an effeective professional (see Walker & Nocon, 2007, for a useful discussion of boundary crossing competence). Initial teacher education can provide opportunities to develop these competencies to help educators grapple with the wicked problems they will experience throughout their careers. Teacher educators have an important role to play in this process and can facilitate boundary crossing by: • preparing educators to face wicked problems in practice: explaining that these are common and promoting a collaborative stance towards solving them; • promoting a view of education as a collaborative endeavour including many partners, all of whom have something to add; • bringing people together to practice discussing -for example by creating ways for those involved in teacher education programmes to discuss wicked problems such as those in the vignett e; • bringing the perspectives of other professionals into the teacher education process using suitable boundary objects e.g writt en resources, visits; • designing resources and activities that promote interrogation of assumptions since seeing from another perspective is crucial to the success of boundary crossing. It is clear that educators face complex problems in their practice that they cannot solve on their own. Collaboration with other stakeholders is frequently needed and this inevitably requires boundary crossing. When professionals collaborate effeectively and engage in mutual professional learning through boundary crossing, they become more effeective as individuals, as teams, and as organisations. Professionals and other stakeholders involved benefi t from boundary crossing; as do the children and students who experience education which is more coordinated, fluexible and responsive to their needs. practice challenge faced by the Scott ish participant. A set of defi ned tasks (boundary object) and tutors (brokers) guided the process. Thee activity required learners to negotiate multiple boundaries -sociocultural, media and technological, vocational and pedagogical -and took learners through the stages of identifi cation, coordination and refluection. Some transformation was identifi ed as an outcome, but was not universally achieved. Thee activity was not without challenges. Theese were primarily logistical in nature, such as fi nding concurrent space and time within two professionally accredited programmes to allow the collaboration to take place. Thee project also revealed the need to secure commitment to the project process and support and encourage communication and reciprocity. In some cases participants cited time as a barrier to engagement and others reported delays and problems making and sustaining contact with partners. In a few cases maintaining effeective communication across boundaries, specifi cally vocational (between disciplines) and technological (associated with systems for communication) was challenging and sometimes insurmountable. However, there were also successes. Participants reported enjoying the collaborative process and becoming more aware of their own and other perspectives on practice. Thee activity resulted in implementation of some innovative approaches in practice and the establishment of some useful professional relationships.
Example 2: professional learning for digital practice Professional learning can also benefi t from a boundary crossing approach. Stimulated by participation in an ERASMUS+ strategic partnership project (Mobile Learning in Higher Education), educators from three sectors in Scotland (Higher Education, Further Education and Community Learning and Development) maintained contact as an informal community of practitioners seeking to develop their own mobile and digital practices. At the time of the stimulus event (a 2 week long Intensive Programme of project activity held in Portugal) some participants were students as well as professional educators, thus this example involved crossing boundaries between roles, sectors, disciplines and countries. Boundary objects were infrequent meetings which took place afther the Intensive Programme and a joint participatory research project which aimed to explore the impacts of the Intensive Programme. Theis project, reported in Cornelius et al. (in prep) revealed that the cross-boundary learning community established supported experimentation, refluection, confi dence and continued learning. Thee stimulus event facilitated the mechanisms of identifi cation, coordination and refluection, and these processes continued to be evident across the three years of the project, allowing participants to sustain and apply learning within their own contexts. Thee opportunity to see challenges from diffeerent perspectives (including diffeerent roles) and discuss challenges free from organisational norms and requirements appears to have been particularly helpful. For example, problems faced by one participant implementing a 'Bring your Own Device' strategy in practice were evaluated from organisational and student perspectives. Participants from diffeerent sectors were able to make meaningful contributions to the discussion free of organisational hierarchies, expectations and restrictions and this allowed a widening of horizons and thinking 'beyond the rules' (Clark et al. 2017). Participants reported signifi cant changes and developments in their practice and pedagogic approaches three years afther the Intensive Programme, suggesting that some transformation had also occurred. Theis example demonstrates the value of long-term boundary crossing as an approach to professional learning and shows that a cross-sectoral approach to the development of digital practice can help to reveal new ideas and approaches and provide solutions to local problems through consideration of alternative perspectives.
Example 3: Inside out -outside in: Building bridges in teacher education through encounters with diversity Experiencing boundary crossing was an important learning process in an interculturally focused project in which student teachers learned together about inclusion and diversity.(Inside out -Outside in: Building Bridges in Teacher Education, 2018) In InOut project we brought together participants (student teachers, teachers and teacher educators) from eight diffeerent European countries for 10 days in an Erasmus+ founded Intensive Programme. Project mainly based on inside-outside theory of Relph (1976). Notions of insideness and outsideness can help student teachers to begin to bett er understand how diffeerent participants locate themselves within educational communities. Participants explored the physical space of the project through, for example, the use of drama, photography, sketchbooks as visual diaries and deriving (boundary objects), and provide opportunities for student teachers to trial these pedagogical innovations in cross-cultural contexts beyond the formal boundaries of school. Therough these activities the project aimed to build bridges through positive encounters with diversity and to support the cognitive, emotional and social learning of future teachers. Thee role of boundary brokers in the project is played by teacher educators on the one hand, but readings and experiences are given at least as important a role in encouraging boundary crossings.

Example 4: Young Entrepreneurs Developing in Action
In a project on entrepreneurship tools were developed to help children engage in entrepreneurial actions. At the same time teachers were trained to promote this process. Thee project was part of a European project to promote entrepreneurship as one of the key competencies of lifelong learning. Students were challenged and facilitated to get in touch with people in the community to try to launch an activity for them that would add value to the community and that would be economically viable. All sorts of examples of initiatives were elaborated. Some children organised a market of things they produced themselves; others elaborated an assignment to organise once a year an exhibition in a local museum; again others launched a crowdfunding project to re-plant a lost forest in a dry area. Thee idea was to promote through teachers entrepreneurial competencies among students. In reality it appeared to be more difficcult to promote entrepreneurship among teachers than among students. Nevertheless, the project made a diffeerence and students involved felt taken more seriously than ever before. Teachers were reluctant at fi rst to allow the freedom to students that would give them room to invent things, have try-outs; be in touch with clients, etc. Teachers worked with fellow teachers from other countries; they also had to cooperate with colleagues from various subject disciplines in school. At the same time they connected to, and met key players in the local community who would be willing to serve as clients in the pilot projects. Thee actual assignments/challenges were the boundary objects that triggered the creative entrepreneurial competencies of students. In this open environment including many players the students were lefth free to launch initiatives.
Example 5: Making use of the historical and cultural context for learning A School is based in the historical centre of the city. Thee city includes a fortifi cation from the middle ages, a cathedral, many old houses, museums and structures from various stages of history stretching as far back as the middle ages. Thee school and the local authorities wish to explore the possibilities of making optimal use of this rich environment for the learning and development of the children; for their social and cultural integration and for their engagement in the community and the sustainability of it, and of its treasures. Teachers together with museum staffe and educational scientists developed a city walk including learnings tasks and assignments, to raise awareness among children of the meaning of the historical background, but also to raise issues for exploring matt ers of identity, the dark sides of the past, and the way people lived and how people perceive things diffeerently each from their own perspectives. In the cooperation between teachers and museum educators new ideas were shared and elaborated on how to implement modes of heritage interpretation that allow children to develop competences for lifelong learning. In the mix of teaching about history, experiencing history and relating it to current issues, museum staffe and teachers developed themselves and each other (Lakerveld & Gussen, 2011). Thee historical context itself was not the object of study, the historical context was used as a context for learning in whatever content domain reaching from languages, to arts, science, creativity, cultural awareness and expression, to technical issues.