- A procedure that can be used to test whether the levels (or groups) of the IV differ on the DVs. E.g., a study consists of two different types of primates, where one primate is “more intelligent” and the other primate is “less intelligent.” The IV is primate intelligence (high intelligence vs. low intelligence) and the DVs are five different questionnaires that each measures, or rates, the participants’ attitudes on the primates. Each questionnaire can measure different attributes that deal with primate intelligence (ex., problem solving, memorization, etc…) A manipulation check would assess if the researcher has effectively “manipulated” primate intelligence. In this example, an independent sample t test would be the appropriate statistical analysis for the manipulation check: five t tests on the five composite scores (from the five different questionnaires) by primate intelligence (high intelligence vs. low intelligence). If the results (per composite score) are statistically significant, than primate intelligence can be said to be effectively manipulated. The IV can be used for further analyses.
- (Can be, but does not have to be?) Included at the end of each questionnaire.
- Checks (each possible comparison) for consistency on the different dependent variables (the questionnaires) by the independent variable (the two groups).
- Included in a study to test the effectiveness of the IV on the different surveys (DVs) in the manner in which the study was intended to be constructed.
