Research that finds out how often and where something (like a race or an age or a behavior) shows up; this kind of study doesn’t look at “cause” and “effect,” and is not “experimental.

a study that focuses on a particular situation or set of situations, reports on important aspects observed, and attempts to determine the interrelationships among them.

A nonexperimental study in which variables or subject characteristics are examined as they naturally occur for the purpose of describing or comparing samples or examining relationships among a set of variables.

Any study that is not truly experimental (e.g., quasi-experimental studies, correlational studies, record reviews, case histories, and observational studies).

A type of epidemiology study where scientists collect information to characterize and summarize the health event or problem.

Studies with no analytic comparisons made between groups. These reports are descriptive in nature.