The subjects included 138 inmates from the prerelease unit of a Southwestern prison system who were randomly divided into three groups of 46 each. Each group viewed a videotaped model delivering a speech on emotional maturity, which was one of the unit's required lectures. The same model appeared in each tape and used the same gestures while being filmed from the waist up; and in all tapes, the model was introduced as a correctional officer from the system's training academy. The independent variable had three levels. In one tape, the model was attired in a shirt and tie; in the second he appeared in a correctional officer's uniform; and in the third, he wore a T-shirt and jeans. After each group viewed the tape, participants were administered a knowledge test and an evaluation questionnaire; the results were tested for significance in relation to the independent variable. Inmates learned the most from the T-shirt model, second most from the coat-and-tie model, and least from the uniformed model. The group that learned the most also evaluated the speaker's knowledge of prison life and work as greater than did the other groups. These findings are viewed as supporting the National Advisory Commission on Criminal Justice Standards and Goals recommendation that the use of uniforms should be discontinued. Related literature is reviewed. Data tables and a 57-item bibliography are included.