Psychology | Methods
Research
Modeling of Cognitive Processes
Cognitive psychology deals with the psychological processes that underlie observable behavior. We can formalize and test assumptions about these latent processes by means of mathematical models. I work with cognitive models like multinomial processing tree models, drift-diffusion models and computational memory models to approach substantive research questions. 
Individual Differences in Cognition
Most psychological theories and phenomena apply to the typical individual: How do people behave or experience something on average? I am interested in how individuals differ: If there is an effect, does it apply to each individual? If not, do people only differ in the size of the effect or even in the direction? In other words, are individual differences quantitative or qualitative? And what drives these differences?
Hypothesis Testing & Model Comparison
Testing hypotheses – predictions derived from theories – is an essential part of the scientific process. In my research, I try to develop and implement statistical methods and make them available for psychologists. The aim is to make psychological research more efficient and more reliable. Among other things, I focus on sequential hypothesis tests, likelihood-ratio based inference, and Bayesian model comparison (i.e., Bayes factors).
Key Collaborators
- Edgar Erdfelder, University of Mannheim
- Daniel W. Heck, Philipps University Marburg
- Stefan Radev, Rensselaer Polytechnic Institute
- Jeff Rouder, University of California, Irvine
- Lukas Schumacher, Heidelberg University