Antitartar Tooth‐Paste: The Statistical Story
SUMMARY A 20-month legal battle between Colgate-Palmolive and Elida-Gibbs, a subsidiary of Unilever, ended in June 1989. Colgate (the plaintiff) accused Unilever of false advertising claims and criticized the scientific evidence put forward by Unilever on both clinical and statistical grounds. The main statistical criticisms were poor experimental design, unreliable data and a result which was unrelated to the product claim. Unilever relied chiefly on the principles of randomization and double-blindness to defend the validity of their findings. The authors, who were statistical advisers to the opposing parties, recount the statistical issues involved in this case.