In a study of the effectiveness of a gluten-free diet in firstdegree relatives of patients with type I diabetics, Hummel et al. placed seven subjects on a gluten-free diet for 12 months. Prior to the diet, they took baseline measurements of several antibodies and autoantibodies, one of which was the diabetes related insulin autoantibody (IAA). The IAA levels were measured by radio binding assay. The seven subjects had IAA units of 9.7, 12.3, 11.2, 5.1, 24.8, 14.8, 17.7We wish to estimate from the data in this sample the variance of the IAA units in the population from which the sample was drawn and construct a 95% confidence interval for this estimate.