This document provides an overview of causal-comparative research. It discusses that causal-comparative research aims to determine the causes or consequences of things that have already occurred. It involves comparing two or more groups that already differ on some independent variable. The key steps include identifying an interest, considering possible causes and consequences, selecting groups to compare, choosing instrumentation, designing the study, and analyzing any threats to internal validity. Analysis of covariance is commonly used to statistically control for extraneous variables between groups.