Utilizing Process Data for Cognitive Diagnosis

Process data, different from item responses, essentially shows the interactions between test-takers, item presentation including stems and options, technology-enhanced help features, as well as the computer interface. With the availability of process data in addition to product data, additional auxiliary information from the response process can be utilized to serve different assessment purposes such as enhancing accuracy in ability estimation, facilitating cognitive diagnosis, and aberrant responding behavior detection. Response time (RT) is the most frequently studied process data contained in log files in current psychometric modeling, although other process data is available such as the number of clicks, the frequency of use of help features, frequency of answer changes, and data collected using eye-tracking devices. Process data is worthy of exploration and the integration with product data can enhance our evidence base for assessment purposes. This chapter will focus on the use of RT as one important type of process data in cognitive diagnostic modeling.