Van Breukelen (this issue) provides an approach to using both response time (RT) and accuracy for (1) measuring latent abilities of participants even when they may trade speed for accuracy, and for (2) providing insight into the psychological processes underlying task performance. In this commentary, I focus on the second of these aims and assess how useful this approach is for exploring cognition. The approach is based on formulating statistical rather than substantive models on accuracy and RT. I focus here on the appropriateness of the RT component model. This RT model joins a family of recent statistical approaches to RT including those of Glickman, Gray, and Morales (in press); Peruggia, Van Zandt, and Chen (2002); Rouder, Lu, Speckman, Sun, and Jiang (in press); Schnipke and Scrams (1997); and Wenger and Gibson (2004). The advantage of these statistical rather than substantive models is robust estimation and sound inference when data are collected across disparate individuals and items. It is not hard to see how these statistical developments will lead to better substantive theory testing and development in cognitive psychology.