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CHAPTER 8: Complex Designs 261FIGURE 8.5Illustration of an interaction effect for a 2 2 2 complex design.A.Low Body-Schema ParticipantsB.High Body-Schema Participants7766Mean Hiring Rating5432Male ApplicantFemale ApplicantMean Hiring Rating5432Male ApplicantFemale Applicant1NormalOverweightApplicant Weight1NormalOverweightApplicant Weight(right panel of Figure 8.5) gave overweight female applicants especially low ratingsbut rated normal male and female applicants the same. Participants whowere low on the body-schema variable (left panel of Figure 8.5), on the otherhand, gave lower ratings to overweight applicants, but the difference betweentheir ratings for male and female applicants was the same for both levels of theapplicant weight variable.One way to summarize the Pingitore et al. (1994) findings shown in Figure 8.5is to say that the interaction effect of the independent variables of the applicants’weight and the applicants’ sex depended upon the participants’ body schema.We call this type of finding a three-way (or triple) interaction effect. As you cansee, when we have a three-way interaction effect, all three independent variablesmust be taken into account when describing the results. In general, when there aretwo independent variables, an interaction effect occurs when the effect of one ofthe independent variables differs depending on the level of the second independentvariable. When there are three independent variables in a complex design, a threewayinteraction effect occurs when the interaction of two of the independent variablesdiffers depending on the level of the third independent variable. The results shown inFigure 8.5 illustrate this well. The pattern of results for the first two independentvariables (applicants’ body weight and sex) differs depending on the level of thethird variable (participants’ body schema). By including the third independentvariable of body-schema, Pingitore et al. provided a much better understandingof discrimination based on an applicant’s weight than would have been the casehad they included only the independent variables of sex and weight.ANALYSIS OF COMPLEX DESIGNS• In a complex design with two independent variables, inferential statisticsare used to test three effects: the main effects for each independent variableand the interaction effect between the two independent variables.