Experimental research in a broad sense refers to a situation in which some condition or conditions are deliberately varied in order that the effect of this variation may be studied often testing specified hypotheses.
A research design that involves random assignment of study participants to either an experimental or control group. This allows researchers to compare the outcome (e.g., test scores) of the experimental group to that of the control group, and to assess the effect of the treatment. The strongest research design for establishing evidence of effectiveness.
research based on, tested by, or having the nature of an experiment.