Probably the most dangerous thing about an academic education […] is that it enables my tendency to over-intellectualize stuff, to get lost in abstract argument inside my head, instead of simply paying attention to what is going on right in front of me, paying attention to what is going on inside me.

Chimamanda Ngozi Adichie.Footnote 1

In brief, the function of knowledge is to make one experience freely available to other experiences.

John Dewey.Footnote 2

1 Introduction

Transdisciplinary approaches serve the dual aim of delivering new knowledge about a situation at hand, and actually interacting with and, hopefully, ameliorating that situation. This ‘action-orientation’ comes with many methodological and practical challenges as to the ‘how’ of transdisciplinarity, but also with a moral obligation to keenly look into the ‘who’-question: whose knowledge counts and comes to bear on dealing with a specific situation? As for those who are included, the question is how they can make their multiple identities come to bear on the issue at hand and how they can effectively use the room for maneuvering that their community of practice or epistemic culture allows them, in contributing to the (transient) transdisciplinary collective. This chapter sets the stage for a close scrutiny of challenges and opportunities in the light of openness and ‘closures’ of knowledge co-production that the chapters collected together in Part 2 of this book deal with, offering a selection of empirical studies that illuminate pertinent conceptual and practical ways forward to inclusive and diverse forms of transdisciplinarity in a variety of contexts. A reason to do so is the conviction that the complex and persistent problems that are center stage in transdisciplinary work require the use of embodied, tacit and situated experiential knowledge of people’s life-world that Ngozi Adichie’s quote in the epigraph directs our attention to, which tends to be absent from most academic knowledge production in efforts at promoting societal transformation.

In this chapter we first give an overview of lessons from the literature on what including diverse groups of actors in transdisciplinary work entails in practice. Then we will contemplate the questions whom to include, when, under what conditions, and to what end, and look into some of the challenges implied in answering these. In conclusion, we briefly introduce the empirical chapters collected in this second Part of the book for practical illustrations of how such challenges can be dealt with in practice.

2 Dealing with Diversities

Various authors have elaborated the why-question posited above, amounting to four ‘canonical’ arguments for including wide varieties of actors in research and innovation (Schmidt, 2020). First, incorporating multiple perspectives in knowledge production on a problem at hand, it is often argued improves research quality (the substantive argument; Lang et al., 2012; Nowotny et al., 2003). Second, legitimacy of and trust in solutions of societal problems will increase, many authors assume, if multiple types of stakeholders contribute substantially to the knowledge that feeds into it (the instrumental argument; Owen et al., 2012; Stilgoe et al., 2013; Von Schomberg, 2013). Third, there is a normative argument stating that whoever will be affected by the outcomes of research or innovation practices deserves to have a say in these (alternatively dubbed, the democratic argument; Cash et al., 2003; Dryzek, 2002; Habermas, 1981; Jasanoff, 2003). Fourth, the inclusion of a wide variety of actors will result in social learning, enabling participants to come to a mutual understanding of diverse relevant values, problem understandings, interests and the like, which will enable them to act in congruence with one another to resolve a situation (the actionable knowledge argument; Hadorn et al., 2006; Innes & Booher, 2004; Klaassen et al., 2018; Loeber et al., 2007).

For these reasons, transdisciplinarity for transformation is about including a diversity of actors, integrating different bodies of knowledge and bringing a diversity of values and perspectives to bear on efforts at ameliorating a problem situation. Transdisciplinarity effectively informs practice because it ties together what Aristotle distinguishes as episteme, praxis and poiesis (Hadorn et al., 2008, p. 31), that is, science, life-world action and production, in a way that informs phronesis: the practical wisdom needed to decide on just and effective actions in the face of some complex, contextually defined issue. For that, such knowledge (‘wisdom’) must enable situated judgment in view of a concrete problem-solving action, and of the ethical choices involved, in a way that does justice simultaneously to the situation at hand and to a more generic understanding as to what is just or wise to do for the community and for humankind (Loeber &Vermeulen, 2007, 2016). While mono- and interdisciplinary work respects the boundaries between the spheres of experiential knowledge holders and practitioners on the one hand and academic experts on the other, transdisciplinary work deliberately transgresses such boundaries—in recognition of the moral and political character of scientific and life-world knowledge.

The development of transformation-oriented knowledge relevant to complex and persistent problems, including the question of how to apply that knowledge in a particular real-life context, often takes place among representatives of a variety of actor groups. In so doing, insights can be unlocked that are vital to finding or co-creating practicable changes for the better, while avoiding exclusion, a priori, of certain groups and the insights these bring to the table, that is, avoiding ‘epistemic injustice’, defined by Fricker (2007) as ‘harming others in their capacity as a knower’.

The recognition of a transdisciplinary approach’s distinctive value also means that more (young) researchers need to get acquainted with doing transdisciplinarity—something also elaborated in the third Part of this volume. The chapters in this second Part of the book are all concerned with a specific, particularly difficult, aspect to this, namely with how to appropriately deal with all sorts of diversities. This comes with challenges concerning the design of transdisciplinary projects and the process of inviting or selecting co-creators. Furthermore, there are challenges in putting transdisciplinarity into practice, enacting inclusivity by making space to genuinely listen to each other and by breaking free from the constraints of one’s epistemic culture, to accommodate information from one’s sparring partners and their needs and values and associate with these through one or more of one’s multiple identities that are less tied in with the dominant epistemic culture.

As for the diversities that deserve to be included, these are many. There is diversity in terms of knowledge and access thereto, diversity in terms of access to resources, distance to and relation with academia, practice, policy and power, diversity in terms of the degree to which one is conventionally allowed to articulate one’s needs, diversity in one’s capacity to articulate one’s needs, desires, problem framings or preferred solutions, diversity in terms of ethnicity, age, gender, sexual orientation—and so on. The various types of differences can exist both between and within actor groups or even individuals and call for a diverse set of approaches to organizing and practicing inclusion. Each of these comes with distinct challenges. The four chapters in Part 2 bring together all have something distinctive to say on the issue of inclusion, and all share a range of lessons for future ‘transdisciplinarians’ to build on. Moreover, since transdisciplinarity yields context-sensitive knowledge, it brings along additional challenges in regard to knowledge sharing. The question is how to communicate insights across contexts in a way that makes ‘experience become available to other experiences’, as John Dewey (1916) put it.

One might think that the type of challenge we are singling out here is not necessarily distinctive to transdisciplinarity. And indeed, as was also discussed in Chapter 1 we find that under various labels and in widely diverging contexts, over the past decades, a wide variety of researchers, practitioners and communities have engaged in building bridges between academic disciplines and practices that go beyond both. We come across terms like co-creation (Mauser et al., 2013; Taylor et al., 2022), co-production (Simon et al., 2018; Turnhout et al., 2020), participatory action research (Díaz-Arévalo, 2022; Gorashi & Ponzoni, 2014; Masson et al., 2021), engaged scholarship (Franklin, 2022) and transdisciplinary research (Klein, 2014; Pohl & Hadorn, 2007)—all used to refer to knowledge production in which disciplinary and academic borders are transgressed. Whether such work is concerned with health system reform (Javadi et al., 2018; Schuitmaker et al., 2021) or nature conservation (Torkar & McGregor, 2012), with the energy transition (Heaslip & Fahy, 2018) or with gender-based violence (Adelman et al., 2012), such efforts tend to be guided by comparable sensitivities and seek to encompass similar values and goals: contributing to positive societal change, in ways that are just and that take into account the needs of those who and that which are most vulnerable and most conventionally ignored—from marginalized groups to threatened wild-life habitats. Of course, this generic characterization leaves plenty of room for variations in all sorts of practical and philosophical details. There are several historical overviews and attempts at analytical description of transdisciplinary research (Balsiger, 2015; Max-Neef, 2005; Popa et al., 2015), so we will not rehearse these here. Rather, we will underscore a small number of observations and lessons to be drawn from past work on transdisciplinary research that we think are relevant for understanding what it means to deal with different actor groups in such work. This includes considering the implications of the fact that all of us are simultaneously member of different professional, personal, cultural or academic communities, and that transdisciplinarity is simultaneously complicated and enriched when it is acknowledged that and how our intersectional positionalities bear on our transdisciplinary practices (Kim, 2023).

We therefore focus on the question on the ‘how’ of inclusive transdisciplinary practices, and on how to do so appropriately. Assessing the level of ‘appropriateness’ of inclusion can be determined on the basis of three themes: (i) the level of integration of different knowledges (Godemann, 2008), (ii) the efficacy or promise of proposed knowledge and solutions to complex persistent problems (Fritz et al., 2019; Lux et al., 2019) and (iii) the contribution to (epistemic) justice as shown by its success in bringing solutions into the world that go beyond the reproduction of existing systems and (power) structures (Loorbach, 2007; Turnhout et al., 2020).

Building on the analysis presented by Vermeulen and Witjes (2020), we can see that these themes correspond with the three strands of scholarly work, promoting the different ‘flavours’ or ‘modes’ of or approaches to transdisciplinarity (see also Regeer et al., 2024). Each flavor is dedicated to the inclusion of different sets of actors and promotes engaging them differently and at different phases of the process of transdisciplinary research.

First, several scholars associate the ‘how’ of transdisciplinary research with the complexity of the problems to be addressed (e.g., Max-Neef, 2005; Nicolescu, 2014). These scholars consider inclusion and diversity issues in seeking to combine a broad range of disciplinary knowledges of academic experts, as a basis for formulating scenarios and policy options. Initial analytic steps, such as problem analysis, problem-definition and preliminary research need to be completed before bringing in actors from practice, and then these actors may well be industry representatives, policymakers and, possibly, civil society organizations (CSOs). The knowledge that citizens might have to offer does not warrant inviting them (Kua, 2016; Rotmans, 1998; Salem et al., 2018). If research is to lead to real-life solutions, however, some degree of integration of different forms of knowledge appears necessary—at least in order to understand the problem being addressed. Despite this, doing transdisciplinary research in this way, even if it is only modestly inclusive and hardly meets the approach to transdisciplinarity that is central to this book, is already quite hard.

A second group of scholars working on sustainability issues in the domain of transition studies (e.g., Geels, 2012; Smith et al., 2005) stress problem solving and ‘implementation support, closely linked to local, regional, national and sometimes even supranational policy making’ (Vermeulen & Witjes, 2020, p. 16). The relative emphasis these scholars place on the efficacy of transdisciplinarity-based solutions to urgent, complex and persistent problems goes alongside more extensive engagement policies. In other words, although it involves very much the same type of actors who are engaged as in the previously discussed ‘flavour’ of transdisciplinary research, which largely excludes for instance citizens, in this type of work these actors take part in more of the transdisciplinary process, and hence, often help co-produce the delineation and definition of the problem.

Third, some scholars have the explicit goal of contributing to increasing (epistemic) justice in doing transdisciplinary work aimed at transforming existing unfair or unsustainable practices (Rodriguez, 2022; Temper & Del Bene, 2016). Empowering vulnerable, marginalized, or other poorly represented and/or heard groups is part and parcel of transdisciplinary work, and itself an aspect of the transformation(s) to work toward. Engaging citizens or bottom-up networks is a much more conventional part of this type of transdisciplinary research than it is of the other two types and in that sense builds on better-known approaches like Participatory Action Research (see Chapter 1).

This volume presents a range of approaches to and practices of transdisciplinary research. Most of the chapters fall squarely within this third type of scholarly work, and those included in Part 2 address the question of how to deal with differences in the distance to or in the boundedness by science, policy, practice and politics that characterize different groups and individuals, and with the associated differences in the language used to articulate needs, values, insights and knowledges. There is no reason to think that there is only one answer to such how-questions. However, the literature draws attention to sensitivities and sensibilities that can help transdisciplinarians think through what does or does not work, what is appropriate and how one might successfully deal with challenges associated with transgressing disciplinary and academic boundaries justly and effectively. The next section briefly discusses some of these challenges.

3 Challenges, Proposed Solutions and This Volume’s Contributions

Arguably, the focus on ‘how’ in discussing the three ‘flavours’ or approaches in transdisciplinarity should also contend with the questions of whom to include, when, under what conditions, to what end—questions that all ‘transdisciplinarians’ will confront at some point. And, of course, also the question how anyone engaged in transdisciplinarity can deal with the different ways in which they are differently bound by different aspects of their positionality, including their ethnic or gender identity, the epistemic culture they were raised in, the community of practice they are member of, and so on, belongs in this list. Answering such questions is deeply political, as any answer will imply including some and excluding other voices (whether they are your own or others’), and relegating different types or degrees of agency and responsibility to groups of differentially interested, affected, distanced, or knowledgeable parties (Chilvers & Kearnes, 2020; Kok, 2021; Soneryd, 2016). We focus on particular challenges that arise and present proposals for dealing with these from each of the different approaches to transdisciplinarity.

3.1 Integrating Knowledges in Efforts to Define the Problem

The main challenge in integrating different forms of knowledge concerns how a problem is framed, finding a common currency in delineating a problem, reaching agreement on what values are (most) relevant and the methods that might be appropriate for developing the necessary knowledge and including the languages each actor uses to realize a shared understanding that many would consider meaningful (Schön & Rein, 1994). All transdisciplinary constellations must contend with these issues. For those focusing on the complexity of the problems (the first ‘flavour’ in transdisciplinary work), this presents the biggest concern. Power differentials among the diverse actors complicate matters considerably. One solution is to set strict ‘rules for closure’, restricting the problem-definition phase to those who have been involved from the outset, and relegating further engagement to ‘end-of-pipe’—arguably at the cost of both the efficacy of proposed solutions and of (epistemic) justice of the research processes and outcomes.

Further complicating issues in integrating knowledge have to do with the composition of the group: how diverse is a transdisciplinary research consortium in terms of disciplinary backgrounds, practical expertise and other forms of knowledge (tacit, experiential, indigenous, et cetera)? Communication skills may also differ, as well as reflexive capacities to support collaboration in inter- and transdisciplinary groups. The emerging group dynamics also matters—especially as often groups are unstable and compositions change over time, and group dynamics tends to be influenced by the degree of the of the group’s heterogeneity in terms of, e.g., (social, epistemic) status and power (Thomas-Hunt et al., 2003).

Given its grounding in distinct real-world problems and its aim to offer practicable solutions to those, groups conducting transdisciplinary projects almost by definition have to develop not just a shared and common knowledge base, but also one that is uniquely geared to the specific situation. Crucially, exchanges within transdisciplinary collectives should not be seen as forms of knowledge transfer, but rather as activities contributing to the expansion of each participant’s perspective and perception of problems and solutions (Godemann, 2008; Regeer & Bunders, 2003). Reflexivity, open-mindedness and responsiveness to other perspectives are necessary but not sufficient conditions for successful knowledge integration (Klaassen et al., 2018).

Difficult and demanding as this might seem, of course the different forms of disciplinary and practical knowledge that various contributors bring is first and foremost a resource. Yet, clearly, different forms of knowledge are structured differently, and communication and cooperation across sub-groups with different knowledges, backgrounds, values and needs complicate knowledge integration (Godemann, 2008). The contribution by Brouwers, Egberts and de Hoop (2024, this volume) illustrates how what they dub a walkshop (Wickson et al., 2015) offers a particular research method that can help bring to life a shared reality in order to support the construction of a common object and research aim. Similarly, in their chapter on the Frame Reflection Lab, Horn and van der Meij outline a hands-on approach to nurturing reflexivity and transdisciplinary collaboration, and to ways to strengthen relevant communication skills.

3.2 Effective Solutions

Issues that result from power differentials among knowledge holders are difficult to brush aside. ‘Transdisciplinarians’ aiming to create a better understanding of real-world and complex problems, as well as at contributing to instigating transformative dynamics, face the challenge of finding ‘ways of working with and around the power relations, which shape and are being shaped by the emerging community’ of the transdisciplinary collective’ (Van Breda & Swilling, 2019, pp. 834–5). The intricacies vary and arguably become notably complex and sensitive if transdisciplinary research also aims to contribute to (epistemic) justice (as is the case in the third ‘flavour’ of transdisciplinarity). Even if we leave aside justice-related issues out of the equation for now, there is a risk that powerful and vested-interest actors use transdisciplinary settings to reproduce the status quo and/or wittingly or unwittingly promote their own self-interest.

This critical risk (see also Stirling, 2008) has been discussed, for instance in relation to participatory experiments in the governance of nuclear waste. Chilvers (2008, p. 1881) discussed the issue, stating that ‘[u]nless [the] often tacit power relations are acknowledged, accounted for, and exposed by all involved, but especially vested interests, [transdisciplinary] analytic-deliberative institutions may well undermine public trust, credibility, and legitimacy rather than promote these democratic virtues as is widely claimed’. As a remedy, there is a need for reflexive and responsive research, as well as governance cultures that authentically support the emancipatory aspirations of transdisciplinarity.

This draws attention to necessary institutional conditions that are, however, seldomly in place. The question is how transdisciplinary research practice can contribute to the normalization of reflexivity and responsiveness in a way that these serve to counter vested interests that reproduce undesirable structures (see also Bourdieu, 1977). The chapter by Ramaswami, Seshadri and Bunders (this volume) shows that phasing transdisciplinary work offers a way forward in this respect, as it enables different actor groups to contribute separately. This makes it possible to make explicit choices about whom to engage at which phase of a project, for what purpose, and together with or apart from which other actors (Lynch et al., 2017; Verwoerd et al., 2023). Thus, separating groups of actors who have more or less power or higher or lower status has proven effective in dealing with this issue (Regeer et al., 2011).

Discussions on power in transdisciplinary processes are inevitably entangled with the debate on how to ensure, without being paternalistic, that vulnerable and marginalized groups are properly engaged. Even if such groups do not pro-actively demand a seat at the table and do not have the same authority or status as other participants—such as corporate representatives, non-governmental organizations (NGOs), policymakers or academic researchers—how can one ensure they fully reap the benefits of transdisciplinary projects? Let us turn to that theme now.

3.3 Epistemically Just Research in Transformation Practices

Among the main challenges in transdisciplinary research is to ensure that it is not only its outcomes that serve those who are less likely to articulate their needs, values and perspectives, but also the research process itself. Co-creation by actors among whom there are obvious power imbalances challenges researchers’ ability to see the less-privileged groups’ knowledges and viewpoints represented in knowledge- and decision-making, without alienating influential stakeholders. As Turnhout and colleagues (2020, p. 16) succinctly put it:

Literature on participation has demonstrated that elite actors, for example from government, large NGOs, or scientists, have more time and resources available, often initiate these processes, define the scope for participation, have more knowledge and skills, and are, for all these reasons that resonate with social-cultural biases, better able to articulate a contribution that is considered relevant and important. Consequently, elite actors are able to shape these processes to serve their interests. In a co-production context, these power inequalities are further compounded by the strong authority that is attributed to scientific expertise vis-a-vis other knowledge systems.

Ignoring power differentials is not an option, as this risks simply reproducing inequities rather than contributing to transforming the status quo (Cooke & Kothari, 2001). And although, fortunately, there are strategies to circumvent this risk, the difficulty of applying these should not be underestimated. Capacity-building initiatives might be useful to ensure equitable access to resources and information, thus empowering groups, but this can only make a substantial difference when also other proactive measures are taken, including learning how to listen well to people whom one does not easily identify with, creating safe spaces for marginalized groups, fostering partnerships or hybrid forums that enable actors to on-line contribute meaningfully to deliberations (Bruhn et al., 2024; Canel et al., 2022; Fritz & Binder, 2020; Mascarenhas et al., 2021; Stark, 2024, this volume). However, another complicating factor is that not everyone whose knowledge, values and perspectives would be pertinent to resolving a given issue is able and willing to participate in a transdisciplinary project. Some people distrust science, or the public authorities that share responsibility for funding or implementing transdisciplinary research and hence might not wish to participate. The chapters by Holle, Ponzoni and Ghorashi and De Weger, Fraaije, Harambam and Willems (this volume) address these issues. These authors show that fostering a culture of mutual respect, and acknowledging the privileges or disadvantages that characterize certain actors is a starting point for dealing with such challenges, although it does not in itself resolve them.

Power is clearly the central theme in all these challenges (and in the chapters addressing them), namely the intricacies in dealing with power differentials. The different ‘flavours’ of doing transdisciplinarity show that dealing with power differentials is a complex process in such research, but is essential to achieve equitable outcomes and engage in equitable practices. As these chapters illustrate, there may be many reasons to navigate power differentials in different ways, depending on the circumstances.

4 Outlook: Signposting Challenges

The challenges discussed above cannot be resolved but must nevertheless be addressed in practice. ‘Transdisciplinarians’ who are dedicated to including diverse actors and factors in their work to help ensure it plays a transformative and emancipatory role have to articulate their own response to such challenges, tailored to the particular circumstances in which their project unfolds. There is not and cannot be one single, universally applicable answer to the question what it entails to include all relevant voices when co-creating practicable knowledge for transformation, just like, as Regeer et al. (2024) discussed, more generally there are no one-size-fits-all guidelines to transdisciplinarity.

As we have already seen, there are many reasons for this. First, diversity in what are regarded complex and persistent problems is too large—just think of the commonalities and differences between institutional racism, biodiversity loss, faltering healthcare systems, climate change, child abuse, food insecurity societal polarization and so on. Second, we must consider the possibility that problems are structured differently, calling for the input of different knowledges, different relevant (epistemic) communities, in which there will be different values at play and so on, and so the goals with which various actor groups engage in transdisciplinary co-creation will also differ. Therefore, ways of making knowledge collaboratively, finding meanings and developing solutions will be different from one context to the next. Third, the institutional, epistemic or governance culture one finds oneself in when engaging in transdisciplinary research can vary significantly, being less or more appropriate for the type of reflexivity and responsiveness required to successfully pool knowledge integration and solution formulation and implementation in just and inclusive ways.

This does not mean, though, that we are forever lost in the dark. On the contrary, we hope that structuring some of the challenges as we have outlined here can be of help to everyone who travels the interesting, complex and (hopefully) ultimately rewarding road of transdisciplinarity.

Much as the analysis we have set out in this introductory chapter acts as signpost to challenges that merit close attention, each of the four chapters in Part 2 present some pointers to what including the right voices at the right time, and using the right engagement practices could mean—or: could for instance mean. None of the authors makes any claim to be comprehensive, or to give recipes for doing things right in terms of inclusion and diversities—to once again touch upon the theme of Chapter 3 of this book. But these chapters do aim to inspire a wide range of readers, practitioners of transdisciplinary work or budding transdisciplinarians.

In their chapter ‘Taking the landscape into conversations’, Brouwers, Egberts and de Hoop show how their development and execution of a walkshop led to more inclusive conversations on preventing wildfires in the Netherlands. The added value of doing inclusivity becomes clear in the way their walkshop promotes engaging with different knowledges and values, while also allowing for the appropriate recognition of the embodied, situated knowledge that emerges in landscape-human interactions, which more conventional and often sterile formats like round-table discussions or one’s everyday post-it session.

The chapter by Ramaswamy, Seshadri and Bunders discusses how transdisciplinarity has enabled systemic transformation in child and youth issues in India, specifically in the area of children’s interface with the criminal justice system, in relation to sexual abuse—in particular the substantial power differences in that system and the conventional disregard for children’s testimonies. Despite these complexities, the chapter celebrates the transformative potential of transdisciplinary work, which becomes clearly visible in the capacity building it supports and in the policy changes it helped advance.

Similarly focusing on a stigmatized, silenced and marginalized community, the chapter by Holle et al. presents three conditions for co-creative research with refugees in the Netherlands. These are creativity, ‘holding space’ for change and transformation and the fluid combination of ‘decentering and recentering’. Using creative workshops to share stories and content through art practices, the researchers aimed at decentering their own perspectives and alleged leading role to allow the group’s desires, knowledges and practices to remain central, recentering when needed—for instance when too much openness risks flowing over into chaos and lack of direction—and incorporating academic insights throughout the process. The chapter illustrates how in transdisciplinary research collectives one can develop ways of working on conducive conditions for fertile co-creation, even when such conditions are not in place.

The final chapter by de Weger, Fraaije, Harambam and Willems presents three different cases, all with different stakeholder groups holding different positions in relation to the interface between science, innovation, policy and practice. The authors focus on the question how to meaningfully engage citizens who experience a distance from, and distrust of, science and government, and who for that reason tend to be excluded in, or choose not to engage in, participatory projects. They discuss pitfalls and (possible) remedies, and once again the authors underscore that ‘transdisciplinarians’ reflexivity is key, as there are no fail-safe solutions.