TY - JOUR AU - TI - STATISTICAL ADJUSTMENTS WHEN COMPARING PREEXISTING GROUPS JF - ETS Research Bulletin Series DO - 10.1002/j.2333-8504.1968.tb00724.x DA - 1968-12-01 UR - https://www.deepdyve.com/lp/crossref/statistical-adjustments-when-comparing-preexisting-groups-Qp0OU3B7HO SP - i EP - 4 VL - 1968 IS - 2 DP - DeepDyve ER -