Experiment-Wise Type I Error Control: A Focus on 2 × 2 Designs

Factorial designs are common in psychology research. But they nearly always used without control of the experiment-wise Type I error rate (EWER), perhaps because a lack awareness about viable procedures for that purpose and also appreciation problem inflation. In this article, key concepts relating to inflation discussed, with emphasis on 2 × factorial design. Simulations evaluate various approaches context. show conventional often do not EWER. Alternative recommended reliably EWER simple implement.