CHANGES IN SUBJECT PERFORMANCE DURING THE SEMESTER - AN EMPIRICAL-INVESTIGATION

Two experiments were conducted to probe for performance differences be tween early-semester subjects and late-semester subjects in an introdu ctory psychology subject pool. In Experiment 1A, hypotheses regarding changes in performance included differential effort, changes in subjec ts' attention to the task, and changes in subjects' sensitivity. A sig nal detection paradigm was used, and 278 subjects were sampled over th e course of the semester. No evidence of changes in subject performanc e was found, in spite of sufficient power to detect relevant patterns of change. The results of a replication (N = 135) were consistent with those of Experiment 1A. Experiment 2 (N = 118) employed a text compre hension task to examine possible differences in subject performance wi th a more cognitive task. Again, there was no evidence to support the idea that late-semester subjects were performing differently from earl y-semester subjects.