A classroom/laboratory exercise has been used to introduce college students to factorial research designs, differentiate between interpretations for experimental and quasi-experimental variables, and exemplify application of laboratory research methods to test practical questions (advertising claims). The exercise involves having randomly divided groups smell either a commercial cologne/perfume or the same product to which musk oil has been added, and then rating the sample on both attracting-repelling and masculine-feminine dimensions. The exercise is presently used in a laboratory section of a beginning course in psychological research methods, but could be adapted to a classroom. Hypotheses generated by students concern the possible pheromone-like qualities of musk oil, based both on known qualities of musk and on advertising claims. Discussion of possible results with students provides an opportunity for: (1) contrasting independent and quasi-independent variables, (2) introducing the concept of interactions and the way they may qualify or nullify main effects, and (3) suggesting the usefulness of multiple dependent variables. After the discussion, students write individual experimental reports of the research. (Author/SW)