The Board of Registry (BOR) certifies medical technologists and other laboratory personnel. The BOR has studied adaptive testing for over 6 years and now administers all 17 BOR certification examinations using computerized adaptive testing (CAT). This paper presents an overview of the major research efforts from 1989 to the present related to test equating. The comparability of both candidate ability estimates and pass/fail decisions on fixed-length paper and pencil (PAP) and CAT tests was initially confirmed in a study in which 645 prospective candidates took both PAP and CAT tests. Two additional studies were then completed using actual certification data. The first study divided the test population into two randomly equivalent groups, 1,669 taking a PAP and 1,699 a CAT examination. Items for both modes were equated to the benchmark scale on which the pass point had been established. Mean ability estimates, standard deviations, and pass rates were comparable. Finally, item recalibrations from CAT were studied with samples of 30, 50, and 100 examinees, and ability estimates correlated at 0.99. These studies confirm that equating with PAP or CAT item calibrations produces comparable candidate ability estimates. (Contains 2 tables, 3 graphs, and 35 references.) (SLD)