This study utilized a pre-, post-, follow-up design for comparison between treatment and control groups to determine the impact of differential treatments upon assertive behavior and locus of control in adult women. The treatments were designed to separate the following assertion training procedures: assertion training, rational-emotive techniques, and rational-emotive techniques paired with assertion training. A one-way ANOVA performed at pre-test time showed no significant differences between groups prior to treatment. Repeated measures ANOVA were computed for all times of testing across all treatments. Significant (p<.05) movement towards an internal locus of control, as measured by the Rotter Internal-External Scale, was found for the assertion/rational-emotive group and the assertion group across pre- to post-test time. No significance was found for the treatment or time/treatment interaction effects with the Rotter. No significance was found for increases in reported assertive behavior, as measured by the Rathus Assertiveness Schedule, across all times and treatments. Significance (p<.05) was found for observed assertive behavior, as measured by the Behavioral Observation Checklist, for the assertion and assertion/rational-emotive group for time/treatment interaction. The Behavioral Observation Checklist was an instrument developed by ~he researcher of this study. Spearman-Brown split-half reliability testing demonstrated the Checklist to be a reliable instrument. Inter-rater reliability was also demonstrated. / Doctor of Education