Integration experts and expertise are crucial for unfolding the full potential of inter- and transdisciplinary (ITD) research. Expanding on the concept of ITD integration, this entry focuses on integration experts, who lead, administer, manage, monitor, assess, accompany and/or advise others on integration across different scientific disciplines (i.e., interdisciplinary integration) as well as across science, policy and practice (i.e., transdisciplinary integration). The entry identifies the diverse roles integration experts play in ITD research projects or programs as integrative leaders, bridge builders, boundary crossers, translators, catalysts, facilitators, contributors, mediators, advisors, or evaluators. It also discloses the personal qualities (e.g., curiosity, sociability, creativity, reflexivity, humility) and expertise (e.g., contributory expertise, interactional expertise, referred expertise) integration experts bring in to realize—together with all other project or program members—the integrative potential of ITD projects or programs.

Integration is often considered the core challenge and the defining characteristic of inter- and trans-disciplinary (ITD) research. Given its importance, it is surprising that the current system of higher education does not provide permanent positions for integration experts; i.e., experts who lead, administer, manage, monitor, assess, accompany, and/or advise others on integration within ITD projects or programs. Based on empirical results of an ITD 2019 Conference Workshop entitled "Is there a new profession of integration experts on the rise?" held in Gothenburg, Sweden, and our own experience in leading and studying ITD integration, the present article sheds light on the overarching question, "What are integration experts?", thus contributing to the emerging literature on integration and integration expertise. We use direct quotes from participants to substantiate workshop results and triangulate them with recent literature on ITD research as well as Science of Team Science (SciTS) and Science and Technology Studies (STS). We conclude our article by discussing possible unintended consequences of establishing academic careers for integration experts, and suggest four complementary ways to support them, while mitigating potentially negative consequences: (a) establishing an international Community of Practice (CoP) to foster peer-to-peer exchange among integration experts, create greater visibility, and develop ideas for transforming academic structures; (b) studying academic careers of integration experts to provide empirical evidence of "successful" examples and disclose different ways of establishing related academic positions; (c) funding respective positions and aligning metrics for ITD research to foster integration within ITD projects or programs; and (d) engaging in collaborative dialog with academic institutions and funding agencies to present empirical results and lessons learnt from (a) and (b) to support them in establishing and legitimating careers for integration experts. If academia is to be serious about addressing the most pressing environmental and societal problems of our time, it needs to integrate its integrators.

In this paper, we develop and apply the concept of 'insight discovery' as a key competence for transdisciplinary research and learning. To address complex societal and environmental problems facing the world today, a particular expertise that can identify new connections between diverse knowledge fields is needed in order to integrate diverse perspectives from a wide range of stakeholders and develop novel solutions. The capacity for "insight discovery" means becoming aware of personal mental representations of the world and being able to shape and integrate perspectives different from one's own. Based on experiences and empirical observations within the scope of an educational programme for Masters students, PhD candidates and post-doctoral researchers, we suggest that insights are the outcome of a learning process influenced by the collective and environment in which they are conceived, rather than instant moments of individual brilliance. The process which we describe, named the insight discovery process (IDP), is made up of five aspects. Within a group setting, a person begins with an "original mental model", experiences an "insight trigger", processes new information within the "liminal space", "formulates an insight" and eventually forms an "adapted mental model". There is a potential for incorporating such process as a fundamental competence for transdisciplinary curricula in undergraduate and graduate programmes by cultivating specific practices and safe learning environments, focused on the enquiry, exchange and integration of diverse perspectives.

The five reflective questions can support leaders of inter- and transdisciplinary projects or programs in better understanding the challenges they experience in meetings or workshops, and in recognizing their own leadership strategies to address them (or not). By assigning explicit time for reflection and considering different integration dimensions, inter- and transdisciplinary research leaders can strengthen their integrative leadership strategies to advance integration in future meetings or workshops.

Theory of Change (ToC) has been promoted as a useful tool in sustainability research for visioning, planning, communication, monitoring, evaluation and learning. It involves a mapping of steps towards a desired long-term goal supplemented with continuous reflection on how and why change is expected to happen in a particular context. However, there is limited reported experience with the development and application of ToCs in inter- and transdisciplinary research contexts. While some previous publications have focused on ex-post application, there has been little discussion about the process of developing and using ToCs in strategic planning and monitoring in large inter- and transdisciplinary research programs. This article reports challenges and lessons learned from the experience of developing and using ToCs in the inter- and transdisciplinary research program Wings (Water and sanitation innovations for non-grid solutions). Challenges include (1) managing time constraints, (2) balancing between concrete and abstract discussions, (3) ensuring diversity in group composition, (4) fluctuating between reservations and appreciation, and (5) fulfilling both service and science roles while leading the ToC process. The experience highlights the importance of alternating formal and informal interaction formats throughout the process, ensuring heterogenous group formation, involving early career scientists, being responsive to emergent needs and making the added value of developing and using ToCs explicit and tangible for all participants. Although these lessons are mainly derived from developing ToCs within the interdisciplinary program team, they can support other programs in both their inter- and transdisciplinary research endeavors.