Interpreting reaction time measures in between-group comparisons

Although reaction time measures have been used extensively in many types of between-group comparisons, the assumptions and limitations of reaction time measurement are not always recognized. In this article we discuss three issues that should be considered when designing and interpreting comparisons involving reaction time. These concern speed-accuracy tradeoffs, methods of analyzing measures postulated to reflect specific processes, and methods for distinguishing group-related influences that are shared with other variables from those that are unique to a single variable.