Experimental research is defined essentially as research in which the causal (independent ) variable(s) can be manipulated in order to change an effect Because of this element of manipulation, researchers in using experimental methods are expected to maintain a good degree of control throughout the period of the study to establish with confidence that cause and effect occurred.
A classic experimental research design in education involves establishing two random groups of students:* one group is a control group that is taught in a traditional manner; a second group is the experimental group that is taught in a new/non-traditional manner. Pre and post tests of student achievement are conducted to determine if a statistically significant difference occurred in achievement. If the achievement in the experimental group is statistically higher than the achievement in the control group, the experiment was a success in demonstrating that the new teaching technique was the cause for the higher achievement effect
studies that seek clues to cause-effect relationships by manipulating one or more factors (independent variables) while controlling others (holding them constant).
Other definition:
Experimental research refers to a study that seeks clues to cause-effect relationships by manipulating one or more factors (independent variables) while controlling others (holding them constant).
Other /More definition:
Experimental research is defined as a research undertaken to discover whether one variable causes another; studies that seek clues to cause-effect relationships by manipulating one or more factors (independent variables) while controlling others (holding them constant).