The California Critical Thinking Skills Test: College Level (CCTST) is a standardized test that targets core college-level critical thinking skills. It has been characterized as the best commercially available critical thinking skills assessment instrument. Building from CCTST validation studies in 1989 and 1990, this paper proposes avenues for further study and suggests ways that the CCTST might be used. After briefly summarizing the conceptual basis of the CCTST, the paper examines questions from the validation studies, which suggest needed inquiry into the differential impact of typical college-level critical thinking (CT) instruction. Preliminary findings indicate differences among students by academic major and by degree of CT self-esteem. Other findings suggest the need for research into factors that predict student CT ability and characteristics of effective instructors. The use of the CCTST in pretest-posttest studies is considered, given that there is only one form of the CCTST. Strategies for development of local CCTST posttest norms and placement scores are recommended. Possible uses of the CCTST in personnel screening and psychological research are outlined. Five tables present data from previous related studies. (SLD)