A computer-assisted technique for analysis and comparison of dose-response curves.

We report a computer-assisted technique for comparison of dose-response curves. Slopes and ED50 values are calculated on the percentage response and the probit transformation of that response, and these are then compared by using an analysis of variance. The technique is much more sensitive than the usual approach of point-by-point comparison and enables several curves to be compared simultaneously. The program, which is written in APL, is interactive and can be used from a terminal by those unfamiliar with computing.