The idea of response times as an important variable in psychological measurement dates back to Francis Galton (1869, 1883) who tried to assess intelligence using the time that subjects needed to respond to a basic stimulus. Due to the lack of methods to accurately assess and statistically analyze the response time data at that time, Galton’s idea did not receive a lot of attention (see e.g., Jensen, 2002). Nowadays, methods to record and analyze response times are generally well available. However, interestingly, although response times have been one of the key focusses in mathematical psychology for many decades already (see e.g., Luce, 1986 for an overview), the interest by psychometricians has been relatively limited. Only recently, interest has grown in adding the item response times to the traditional psychometric analysis of the item responses. Currently, many new methods are being proposed that extend existing psychometric tools (like the two and three parameter item response theory models) to include the item response times as an additional source of intra- and inter-individual differences. With these response time methods in place, question arises what the actual contribution is of the response times to the measurement of psychological and educational constructs.
In the present talk this main question is addressed by discussing the historical background, the objective, the methods, and the future of response time modeling on the basis of the What, Why, How, and Where of psychometrics and response times:
- What brought psychometrics and response times together?
- Why are psychometricians interested in adding the response times to the analysis of the responses?
- How can we extract the desired information from the response times using the current state of the art psychometric approaches?
- Where does the scientific study of response times ultimately bring us?