The effect of expectations on the task performance of vocational trainees with mental retardation

This study investigated if three treatment conditions; namely, increased individual, staff, or a combination of both individual and staff expectations had an effect on the task performance of vocational trainees within the borderline to moderate range of mental retardation. To address this question, 80 subjects were chosen at random and divided into 20 blocks based on full-scale I.Q. They were then randomly assigned to a treatment or control group. The result was a randomized block design with 4 groups of 20 subjects blocked according to full-scale I.Q. and randomly assigned to one of the three treatment groups or to the control group. The study was conducted between May 16, 1988 and August 19, 1988. After obtaining each subject\u27s informed consent by having them or their legal guardian sign the Marquette University Agreement of Consent form, they were administered the Purdue Pegboard Test. Subjects in treatment groups 1 and 3 were verbally informed that the test predicted that their production would increase in the next few weeks. The supervisors of the subjects in treatment groups 2 and 3 were informed, in writing, that these particular workers\u27 production rates would increase in the next few weeks. The subjects in group 4 were administered the Purdue Pegboard Test only. After an eight week period, the subjects\u27 production and percentage rates were collected and analyzed along with demographic and interview information. An analysis of variance, fixed effects model, revealed no statistically significant differences between the treatment groups and the control for post production rates (F =.610: d.f. = 3,76; p $\u3e$.05) or normative percentage rates (F =.503: d.f. = 3,76; p $\u3e$.05). A multiple regression analysis resulted in a significant correlation between full-scale I.Q. and the Purdue Pegboard Test scores ($p\u3c$.001), post production rates ($p\u3c$.01), and normative percentage rates ($p\u3c$.001). In addition, the variable of age significantly correlated with years employed by agency ($p$ $\u3c$.001), and the scores on the Purdue Pegboard Test ($p\u3c$.05). Interviews indicated that 50% of the supervisors expected increases in production and 80% of the subjects expected increases in their production