THE MODIFIED TRIANGLE TEST

The triangle test has been used very frequently in sensory difference testing. Attempts have been made to augment the basic information from triangle tests with scores on degree of differ ence between the sample selected as the variant and the remaining two. A mathematical model has been developed to permit formal utilization of the degree of difference scores. It is summed that a stimulus-response scale exists and that two standard samples and one variant sample evoke responses x sub 1, x sub 2, and y on this scale. These responses are taken to have inde pendent normal distributions with variances signal squared and means zero for the x-variates and mean mu for the y-variate. Conditional dis tributions for degree of difference scores are obtained, the likelihood function for N inde pendent trials of the triangle test is developed, and a procedure for testing that mu 0 is given. The procedure considered is designated as the modified triangle test and illustrations of its use are shown.