in marketing and advertising research, a technique that utilizes a controlled situation, in which one or more factors are manipulated by the marketer or advertiser, for example, allowing subjects' behavior to be monitored to determine cause and effect; can be useful in helping to determine the impact of an increase in the advertising budget or the use of specific media vehicles. Essentially, the manipulation of an independent variable (e.g., advertising dollars) to observe the effect on a dependent variable of interest (e.g., sales) to the advertiser or researcher. Often used to compare the responses of two or more groups that are alike in all ways except for the variable being tested. Typically involves comparing a “test group” with a “control group,” or the group not receiving the test treatment. See independent variable and dependent variable.