Evaluation is a major issue in discussions of transdisciplinary research (TDR). Empirical studies often consider expert perspectives; however, knowledge of the experiences, attitudes, and motivations of a broader science-practice community applying transdisciplinarity remains rare. The present study aims to gather insights into the perceptions and assessments of success of TDR projects from scientists and practitioners with experience with TDR processes. Based on a mixed-method approach combining qualitative expert interviews with a quantitative survey reaching 178 respondents from practice and science, the results show a high commitment to the targets of TDR projects and a basic shared 'success profile'. Nevertheless, there is currently a strong 'practice tendency', while TDR-specific benefits of the scientific knowledge gain remain neglected. The general success assessment of TDR projects can be described as rather moderate, indicating several deficits in the application and management of TDR.
Keywords: Cooperation; Evaluation; Quality measurement; Research evaluation.