When a researcher has no control over the variables and can only report what has happened or what is happening, such research is called

Ex post facto research studies effects after they have occurred, with no control over the variables.

The researcher only reports what has happened or is happening.

Because the presumed cause already occurred, it cannot be manipulated.

Clinical research investigates diagnosis and treatment of disorders.

Diagnostic research seeks the causes or nature of a specific problem.

Ex post facto designs can suggest but cannot firmly establish causation.