Over the last several decades student affairs and assessment scholars who study college impact have utilized a number of different research design and statistical procedures in an attempt to control for the characteristics and propensities that lead students to self-select themselves into a particular intervention or experience. This is particularly important because such characteristics and propensities may seriously confound any estimate of the effect of the intervention or experience itself. In this study the authors employ both covariate adjustment and propensity score matching to estimate the causal influence of an example intervention--the first year of attendance at a liberal arts college (as opposed to another type of 4-year institution). Specifically they estimated the effect of liberal arts college attendance on three cognitive outcomes. They examined the estimates yielded by these two analytical approaches under different research design assumptions--with and without a precollege measure of each outcome. Their purposes were to determine the comparability of causal estimates using covariate adjustment and propensity score matching, and to examine how these estimates might be affected when different research designs are employed to study college impact. (Contains 1 table.)