Further evidence regarding instructional effects on frequency judgments

Previous experimental reports have provided contradictory evidence regarding instructional effects on frequency judgments. An experiment was performed to clarify these findings, in which frequency discrimination was compared for two groups of subjects. One group was instructed as to the nature of the forthcoming frequency judgment task, while the other was told to prepare for an unspecified memory task. To avoid the possibility of response bias effects, the frequency discrimination coefficient, a correlational measure, was used to assess performance. Howell’s 1973 finding of no instructional effects on frequency judgments was replicated. An attempt is made to reconcile this result with the finding by Begg and Rowe that subjects in a continuous frequency judgment task gave unusually accurate mean frequency judgments compared to subjects who were tested following study of all items.