Denny Borsboom, University of Amsterdam

2025 Presidential Address

Basic psychometric models, like the factor model and the Item Response Theory model, were originally constructed to mimic successful measurement setups in physics, often by analogies with the measurement of physical quantities like length. In the present talk, I will argue that for many psychological and educational phenomena, these analogies do not work, because the underlying psychological theory that would motivate them is highly implausible. Instead, for many cases the analogy of ecosystems is more fitting. In this view, measurements can be viewed as recordings of the states of observable parts of the system. Because these observable parts are mereologically rather than causally related to the system as a whole, the relation between observed scores and system states should not be construed in terms of causality but in terms of supervenience: differences in observables are necessary but not sufficient for differences in the state of the system. I will sketch the outlines of a psychometric theory that does justice to this perspective using insights from network modeling and formal theory construction. In addition, I will argue that in this perspective old psychometric workhorses like the sumscore receive a convincing alternative interpretation as index variables that track the functioning of the human system, rather than as measurements of underlying psychological constructs.

about the speaker

Denny Borsboom is Full Professor of Psychological Methods at the Psychology Department of the University of Amsterdam, and director of its Social and Behavioural Data Science Centre. His research focuses on the conceptual analysis of psychometric concepts, the development of new psychometric techniques, and the construction of formalized psychological theory. Borsboom’s research on the use of complex systems and network models in the context of psychometrics and psychopathology research is concentrated in the Psychosystems Project. The Psychosystems team developed alternative representations of psychological constructs as networks of interacting variables, which has led to innovative methodologies to estimate such structures and to new theories of psychopathology. Recently, he has started developing methodology to promote formal theory construction in psychology, a research line that is concentrated in the Theory Methods Lab. Denny Borsboom is the current President of the Psychometric Society.