Case - Body on Tap
A few years ago Vidal Sassoon, Inc., took legal action against Bristol-Myers over a series of TV commercials and print ads for a shampoo that had been named Body on Tap because of its beer content.12 The prototype commercial featured a well-known high fashion model saying, "In shampoo tests with over 900 women like me, Body on Tap got higher ratings than Prell for body. Higher than Flex for conditioning. Higher than Sassoon for strong, healthy-looking hair."
The evidence showed that several groups of approximately 200 women each tested just one shampoo. They rated it on a six-step qualitative scale, from "outstanding" to "poor," for 27 separate attributes, such as body and conditioning. It became clear that 900 women did not, after trying both shampoos, make product-to-product comparisons between Body on Tap and Sassoon or between Body on Tap and any of the other brands mentioned. In fact, no woman in the tests tried more than one shampoo. The claim that the women preferred Body on Tap to Sassoon for "strong, healthy-looking hair" was based on combining the data for the "outstanding" and "excellent" ratings and discarding the lower four ratings on the scale.
The figures then were 36 percent for Body on Tap and 24 percent (of a separate group of women) for Sassoon. When the "very good" and "good" ratings were combined with the "outstanding" and "excellent" ratings, however, there was only a difference of 1 percent between the two products in the category of "strong, healthy-looking hair." The research was conducted for Bristol-Myers by Marketing Information Systems, Inc. (MISI), using a technique known as blind monadic testing.
The president of MISI testified that this method typically is employed when what is wanted is an absolute response to a product "without reference to another specific product." Although he testified that blind monadic testing was used in connection with comparative advertising, that was not the purpose for which Bristol-Myers retained MISI. Rather, Bristol-Myers wished to determine consumer reaction to the introduction of Body on Tap. Sassoon's in-house research expert stated flatly that blind monadic testing cannot support comparative advertising claims.
Question
Comment on the professionalism of the procedures used to make the advertising claim. Why do you believe the researchers performed the data transformations described?