A Computerized Stroop Experiment that Demonstrates the Interaction in a 2 × 3 Factorial Design

Abstract

This article describes a computerized Stroop-type experiment that demonstrates the effects of an interaction in a factorial design. The independent variables in this experiment are (a) the presentation of a congruent color word with a color bar or the presentation of a conflicting color word with a color bar and (b) the spatial placement of the color word above, on, or below the color bar. The dependent variable is the reaction time for the subject to say the color of the bar. Data for six semesters of an experimental psychology lab course indicate a significant difference between the conflicting and congruent conditions and a consistent significant interaction between the two independent variables. The computer program that runs this experiment is described, and explanations for the interaction are discussed.