This study examined differences in achievement over Person- Centered Therapy and Rational-Emotive Therapy taught by adjunct computer-assisted instruction tutorials (CAI) and traditional instruction (TI). The Achievement Instrument Over Person-Centered Therapy and Rational-Emotive Therapy was developed by the researcher to measure achievement. Content validity and test-retest reliability were established for the test. Analysis of covariance was utilized to test for differences in achievement gains between the CAI and TI groups. Cumulative university grade point averages and achievement pre-test scores were covariates. The Kolmogorov-Smirnov test was used to determine if the distribution of scores following instruction would be more positively skewed for the CAI group than for the TI group. This effect was expected if CAI was more effective than TI for low ability students.