In mixed methods approaches, statistical models are used to identify "nested" cases for intensive, small-n investigation for a range of purposes, including notably the examination of causal mechanisms. This article shows that under a commonsense interpretation of causal effects, large-n models allow no reliable conclusions about effect…

Describes a teaching activity that improves students' scientific reasoning by focusing attention on the causal, explanatory nature of psychological theories. Students learn and use an argument form called Inference to the Best Explanation (IBE). Includes examples of this technique and student responses to the course. (MJP)