Glossary of Research Methods

Cases

The units of analysis in a given study. The political, social, institutional, or individual entities or phenomena about which information is collected and inferences are made. Examples include nation-states, social movements, political parties, and episodes of policy implementation.

Case Study

A research design focused on one or a few cases, typically analyzing the case(s) in great detail through cross-case or within-case analysis.

Causation

A causal pattern in which (a) alternative combination of factors can produce a given outcome; any one of these causal paths may involve the interaction of two or more explanatory factors.

Concept

Variously understood as an abstract idea that offers a point of view for understanding some aspect of our experience; a mental image that, when operationalized, helps to organize the analysis of data.

Correlation

A measure of association between two or more variables.

Cross-sectional analysis

Research that focuses on multiple cases at one point in time.

Dependent variable

What the researcher seeks to explain. It is hypothesized to be caused by, or “dependent” on one or more independent variables. It is also called an outcome variable.

Empirical

Based on observation and evidence

Hypothesis

A tentative answer to a research question. In a causal analysis a hypothesis is a conjecture about the relationship between one or more independent variables and a dependent variable.

Longitudinal analysis

Analysis of change over time, focused on one or more variables or cases.

Research Design

A plan for carrying out a given study, common involving a sequence of research steps.

Research question

The theoretical or empirical puzzle that motivates a given study.

Regression Analysis

An extension of correlation analysis, which makes predictions about the level of the dependent variable using data about one or more independent variables.