Key research themes
1. How can changes in response processes affect the validity and interpretation of longitudinal patient-reported outcome measurements?
This research area investigates the phenomenon of response shift, which occurs when the meaning of a respondent’s self-evaluation changes over time, particularly in the context of patient-reported outcomes (PROs). The focus lies on defining response shift, developing theoretical frameworks, and refining methods to detect its occurrence in longitudinal studies. Accounting for response shift is critical because unrecognized changes in response processes can bias inferences about true health changes and affect the validity of clinical and policy decisions based on PROM scores.
2. What are the mechanisms, types, and statistical interrelations of response effects such as mediation, confounding, suppression, and response biases in psychological measurement?
This theme encompasses the conceptual and statistical distinctions among mediation, confounding, and suppression effects, exploring their mathematical equivalences and differences in interpretation. It also covers systematic response biases present in self- and other-report questionnaires, including acquiescence and extreme responding, as well as social desirability biases. Understanding these biases and effects is fundamental for designing valid instruments, controlling for measurement error, and interpreting observed relationships in psychological and behavioral data.
3. How can response time and accuracy interdependence be modeled to better understand cognitive and behavioral processes?
This research area focuses on jointly modeling response time and accuracy data to infer underlying mental process architectures and to capture conditional dependencies between speed and correctness beyond overarching latent traits like ability and processing speed. By extending traditional hierarchical IRT frameworks and incorporating residual dependencies, these approaches reveal nuanced insights into item properties and respondent behaviors, advancing precision in psychological and educational measurement and process modeling.