This document discusses different research methodologies including survey research, correlation research, and causal-comparative research. It provides details on the purposes and types of each methodology. For survey research, it identifies three common longitudinal study designs: trend studies, cohort studies, and panel studies. Correlation research examines relationships between two variables, either to explain behaviors or predict outcomes. Causal-comparative research attempts to determine causes or consequences of pre-existing differences between groups. Examples of topics that could be studied with each methodology are also provided.