Repeated Measures on a Choice Reaction Time Task
The current investigation examined a visual choice reaction time (CRT) task to determine its suitability for repeated measures experimentation. Fifteen Navy enlisted men served as subjects for one-, two-, and four-choice reaction time conditions. Fifty trials on each condition were administered for 15 consecutive workdays. Reaction time (RT), movement time (MT), and total time (TT) were recorded for each trial. Results indicated that across all RT conditions, intersession correlations were differentially stable by about Day 8, with reliabilities around .71. Means remained unchanged over the stable days and variances remained constant across all 15 days of the experiment for the RT measure. It was concluded that studies using RT as the dependent variable should allow for sufficient RT practice prior to data collection to ensure that the results are not contaminated by learning effects. It is recommended that at least 1000 practice trials be given prior to using an RT task to assess the effects of an environment.