Reliability of a sentence completion measure of ego development.

Studied the reliability of the Washington University Sentence Completion Test by giving 51 9th graders and 26 college students the test twice, a week apart. For 9th graders the design included a test-retest group and two groups given half of the test at each session. Although test-retest correlations were high for the 9th graders, retest scores dropped significantly. With college students (a) test-retest correlations through positive and significant were lower, (b) retest scores did not change systematically, and (c) percentage agreement between test and retest scores was high. Discrepant results were related to motivational set and variance in test scores. Split-half correlations and internal consistency coefficients were high. Likelihood of lower retest scores makes problematic the use of this test for short term pretest-posttest studies seeking to stimulate ego development.