What makes biomedical knowledge specific, sensitive, reliable, or valid? How have biomedical scientists used these evaluative categories in practice throughout the twentieth century? Inspired by these questions, seven members of the Max Planck Research Group “Practices of Validation in the Biomedical Sciences” will collectively explore questions about validity from within and beyond the epistemic boundaries of their disciplinary approaches.

The notion of validity has haunted practical scientific endeavors across historical eras, though the technical term "validity"—one with a complex genealogy from logic and statistics to psychology—first came about in the twentieth century. The term denotes the extent to which an assessment of an item actually captures what it intends to capture. Investigating how concepts of validity and associated techniques have informed research, clinical, laboratory, and health practices in the nineteenth to twenty-first centuries calls for a cross-disciplinary approach. Our collective aims are, first, to interrogate validity, its history, philosophy, and social nature, and to identify what can be learned by the diverse findings from one biomedical science to the next. We will draw on concrete evidence in our respective fields to elaborate on the emergence of various concerns related to validity in medical parasitology, pain measurement and management, animal welfare sciences, psychophysics, psychiatry, translational medicine, and meta-analysis of clinical trials. Secondly, we aim to enrich an understanding about the role of validity in the biomedical sciences across the disciplinary boundaries of historical actors. A moderated round table discussion, including the audience, will probe the concerns that gave rise to validity and how validity coordinates knowledge through scientific, institutional, and administrative practices in a cross-disciplinary perspective  and also offers an opportunity to reflect on the nature of an interdisciplinary research group in the humanities.