Yesterday, we posted an interview with Laura Brett, the Director of the NAD, in which Brett discussed various issues, including how the NAD is evolving, how Brett sees herself as different from her predecessor, and how the NAD decides cases. Today, we’ll take a brief look at one of those cases that involves a perennial topic at the NAD – product testing.

DKB Household USA advertised that its Zyliss SwiftDry Salad Spinner “removes 25% more water than other salad spinners.” In response to a challenge brought by one of its competitors, DKB produced an independent third-party test that compared the performance of various salad spinners. The NAD was concerned by three key aspects of the test and the results:

First, the test was conducted on “simulated salad leaves” – cloths and sponges – rather than on actual greens. The NAD has consistently held that the most reliable measure of a product’s performance is demonstrated by tests that evaluate the product in the same manner the product is directed to be used by consumers. Although there may be reasons to deviate from that standard, the NAD was not convinced that DKB’s reasons were valid, in this case.

Second, DKB did not present a statistical significance of the test results. The NAD has consistently held that results should be statistically significant,  generally at the 95% confidence level. In this case, there was a small sample size and wide variations in the test results. “In the case of comparative performance claims, small sample sizes may not reliably demonstrate the claimed performance of the product.”  Accordingly, the NAD was “especially concerned that the test involved only five trials of each product.”

Third, DKB only tested its salad spinner against products sold by two competitors (including the challenger). The NAD noted that in order to support a broad superiority claim, “an advertiser must test a variety of competing products that comprise all or a substantial portion of competitive products the market.” In this case, there was no evidence in the record that the products tested comprised all or a substantial portion of competitive products.

Although there’s nothing groundbreaking in this case, it neatly encapsulates three key principles advertises should know: (1) products should generally be tested in a way that mirrors consumer use; (2) results must be statistically significant; and (3) to support an unqualified superiority claim, an advertiser must at least test against a substantial portion of competitive products.