The objective of the study was to determine whether Competency-Based Testing (CBT) schools altered their curriculum differently than Non-Competency-Based Testing schools (NCBT), and, if so, what selected factors were identified as contributing to the differences among the responses secondary schools made to CBT. The data from 410 member high schools of the North Central Association of Colleges and Schools were collected from "Form A: Annual Report, North Central Association of Colleges and Schools" and a researcher-developed questionnaire. The questionnaire was returned by 85 percent of the principals of schools surveyed. The chi-square test of association applied at the .10 level of significance was utilized to test for significant association between competency-based and non-competency-based testing alone; then high schools isolated first by community type, then school size, and then ethnic makeup. Among the conclusions reached from the study were: CBT schools were doing little significantly different than NCBT schools; CBT schools stressed "basic" courses and remedial courses more than NCBT schools; and in an effort to address the narrowing of the curriculum, schools were adjusting courses by combining them, offering them in single sections or at alternate times, or changing their internal structure. (PN)