The purpose of this study was two-fold: (1) to determine the effect of internal-external control on retention of control-relevant versus non-control relevant information, and (2) to investigate differences among internal and external prison inmates in their participation in occupational education programs. The sample of 216 inmates, ranging in age from 18 to 65 years, were from a correctional institution in North Carolina. The treatment consisted of manipulating the perceived relevancy of parole information to the prison inmate's chances of achieving parole. The data are presented in three parts, by test of (1) the retention hypotheses, (2) hypotheses concerning participation in occupational education, and (3) reliability of the instruments used in the study. It was concluded that a person can be described as possessing a generalized expectancy of control or lack of control over his environment, and that this characteristic can affect his willingness to learn information or engage in activities that could reasonably be expected to increase his chances of control over his environment, such as participation for employability. (CH)