Ordinal Position Effects on Speed-Accuracy Trade-Off in Absolute Judgment

The speed-accuracy trade-off function was determined for an absolute judgment task with ten equally likely stimuli. The mean trade-off shape was found to be similar to previously reported date. However, when the trade-off was computed separately for each stimulus, ten distinct curves were obtained which were shown to he not randomly distributed around the mean curve, this indicating a particular processing of some stimuli. These ordinal position effects on the parameters of the functions are interpreted as providing evidence that some cognitive strategy is involved in identification performance. It is finally suggested that a detailed analysis such as that reported might allow a sharper testing of some decision models.