The systematic elimination of extraneous variables, other than those you are interested in, can be done in which of the following types of research?

Experimental research allows systematic elimination or control of extraneous variables to isolate the effect of interest.

Qualitative research studies meaning in natural contexts and does not strip away variables.

Longitudinal research follows subjects over time but does not by design remove extraneous influences.

Correlational research measures existing relationships without controlling outside variables.

Control techniques include randomisation, holding conditions constant and matching groups.

This control gives experiments their strength in establishing causal claims.