Transdisciplinary research unites scientists and practitioners from diverse backgrounds to tackle complex societal and ecological challenges. A crucial aspect of this collaborative knowledge production is integration, an open-ended learning process encompassing cognitive-epistemic, social-organisational, and communicative dimensions. Effective integration relies on transparent and structured communication at eye level between all participants. Existing studies emphasize the importance of communication tools (CT) in transdisciplinary projects, but their specific impact on integration's various dimensions remains largely unexplored. This study addresses this gap by analyzing the role of CT in supporting integration within a 3.5-year transdisciplinary project, the "Empowerment, Self-Organisation and Regional Transformation—the model of the Club of Rome Region Carnuntum" (RLC 2040) project. We hypothesize that integration in transdisciplinary projects depends on participatory methods, personal communication, and supportive CT, and aim to determine how different CT support the various dimensions of integration among diverse actor groups within this project.

The literature highlights the critical role of effective communication in transdisciplinary research for achieving integration. Several studies underscore the importance of balanced and targeted communication facilitated by specific tools. These tools are seen as crucial for bridging knowledge gaps, promoting shared understanding, and fostering collaboration among diverse actors. While the importance of integration is widely acknowledged, the specific support provided by different communication tools for each dimension of integration remains under-researched. Existing classifications of communication tools vary, considering aspects like communication direction (unidirectional vs. reciprocal), temporal aspects (synchronous vs. asynchronous), semiotic modes (auditory, visual, textual), and organizational context (internal vs. external). The literature also emphasizes the significance of considering different actor groups (scientists, practitioners, integration experts) and their specific communication needs. The concept of 'integration expert' as a facilitator of transdisciplinary integration is also discussed, highlighting their role in managing and promoting integrative processes.

This study employed a multi-methods approach to investigate the role of communication tools in supporting integration within the RLC 2040 project. The project involved 80 practitioners (Future Council members), 6 scientists, and 3 integration experts. Ten communication tools—a mix of digital (digital pinboards, digital videoconferences, mailings, online voting, project websites) and analogue tools (orientation poster, presentations on websites, minutes, short films, sketchnotes)—were utilized. Data were collected through three online surveys at different project phases (OS1, OS2, OS3), an ex-post poster assessment (n=46), and six interviews with scientists and practitioners. The surveys gathered information on tool usage, perceived support for collaboration, and reasons for non-usage. The poster assessment evaluated the tools' integration support across three dimensions (social-organisational, cognitive-epistemic, communicative) using a five-point Likert scale. Interviews provided in-depth insights into participants' perspectives. Minutes from project team meetings and reviews supplemented the data. Quantitative data from surveys and poster assessments were analyzed descriptively, while qualitative data from interviews and meeting minutes underwent content analysis. The analysis focused on the tools' support for each integration dimension and how different actor groups perceived them.

The analysis revealed that a variety of communication tools can effectively support integration in transdisciplinary projects, catering to the diverse needs of different actor groups. The project website emerged as a central information platform, providing crucial orientation and access to project information for all participants. The orientation poster and sketchnotes, although involving one-way communication, were highly valued for providing quick overviews and understandable summaries, particularly supporting the communicative and social-organisational dimensions of integration. Digital videoconferences performed best in facilitating the cognitive-epistemic dimension, proving effective for information exchange and knowledge sharing. In contrast, mailings, online voting, and minutes were perceived as less supportive of integration. The involvement of integration experts with diverse communication and visualization skills was crucial in adapting tool choices to specific contexts and needs. Communication tools perceived as most supportive were those utilizing visual and textual systems and fostering a strong sense of group identity. This suggests that an emotional dimension should be added to the existing model of integration.

The findings confirm the supportive role of communication tools in transdisciplinary research, extending previous research by examining their influence on multiple dimensions of integration. The success of tools like the orientation poster and sketchnotes highlights the importance of visual communication and the creation of a shared group identity. The high effectiveness of videoconferencing underscores the continued need for synchronous interaction in addition to asynchronous tools, while the lower ratings of email, online voting, and minutes show the limitations of purely textual and asynchronous communication. The significant role of integration experts in facilitating effective communication and adapting tools to project context underscores the need for specialized expertise in managing transdisciplinary projects. The identified need for an additional emotional dimension of integration suggests a more holistic understanding of integration in transdisciplinary research is necessary. This highlights the importance of considering not just cognitive and communicative aspects, but also the emotional and social dynamics that influence collaborative processes.

This study demonstrates the significant role of communication tools in supporting integration in transdisciplinary research. The findings emphasize the importance of a multi-faceted approach, incorporating visual and textual communication, synchronous and asynchronous tools, and fostering a strong group identity. The study highlights the value of integration experts with diverse skills, and suggests the need for future research to include and operationalize an emotional dimension of integration. Further research should focus on developing more robust scales for measuring integration dimensions, investigating the relationship between specific tools and knowledge integration methods, and exploring how to improve inclusive communication in transdisciplinary projects.

This study's limitations include the reliance on ex-post assessments, potentially leading to recall bias. The explorative operationalization of integration dimensions might have limited the precision of the analysis. The self-selection of participants in the final Future Council meeting could have skewed the results. Furthermore, the study did not extensively assess the quality of the individual communication tools themselves, only their perceived support for integration. Future studies should utilize more comprehensive methodologies, such as longitudinal studies and more detailed qualitative analyses, to address these limitations and gain a more nuanced understanding of the impact of communication tools on transdisciplinary integration.