No abstract

No abstract

In twenty nonreinforced binary chQices, adolescent retardates, normal children, and college students gave no more alternations when instructed to respond randomly than when instructed to respond with a simple pattern. These results imply that alternation above chance is due to something other than preconceptions about the nature of random sequences.

This study was concerned with whether percent-choice data in probability learning include subclasses with different choice proportions. When the positive alternative was on the right, percent choice of the positive alternative was significantly greater, even at asymptote. Choice latency was also recorded; there was a significant tendency to respond more rapidly when an asymmetrically located reinforcement signal was on the right or when it was on the side opposite the positive alternative. The percent-choice data did not show corresponding significant effects. These findings suggest that percent-choice measures may pool a variety of different ways of responding that are differently affected by experimental variables.

Sixty-seven middle-grade and 53 high-grade retardates were assigned to either control or experimental binary-choice-task groups. Control sUbjects were invariably reinforced.) regardless of choice. Various response patterns were differentially reinforced for experimental subjects. Single alternation was overwhelmingly preferred) and there was little choicese~uence pattern variability. These results were attributed to a lowered tendency in retardates to avoid long se~uences of alternation responses.