This study investigated the effect of timed testing on developmental students' scores and developed data that might better reveal students' reading and testing behaviors. Three tests were administered to provide six variables, including the Cooperative English Test, Form 1A (Coop 1A); Cooperative English Test, Form 1B (Coop 1B); and Degrees of Reading Power, PA-2. Subjects were 95 students in four community college developmental reading classes conducted during the fall 1984 semester. Results showed that the relationship between developmental students' scores on untimed reading tests is positive. However, the correlations between scores on a time-critical reading comprehension test and two untimed reading tests are negligible, and these low correspondences are attributable to the timing variable. Timing or the speed set it elicits not only effects scores, but also the manner in which a test measures. It was learned that developmental students' scores on a time-critical test are profoundly affected by students' speed of response. It is apparent that time-critical reading comprehensive tests, which critics view as unsuitable for student populations as a whole, are even less appropriate for developmental students whose rate behaviors are comparatively slower. (LMO)