A LARGE‐SCALE EXPERIMENTAL COMPARISON OF THE TETRAD AND TRIANGLE TESTS IN CHILDREN

Abstract

ABSTRACTInterest in the Tetrad test as an alternative to the Triangle test is growing as theoretical results indicate that the Tetrad test has relatively high power for an unspecified method. But a large‐scale experimental comparison of the Tetrad test with the Triangle test for the same stimuli has not yet appeared in the sensory literature. In this paper, we report results from such a large scale comparison, with the addition that the testing was conducted with children. This comparison is important as the presence of a fourth stimulus in the Tetrad test could lead to reduced effect sizes due to sensory fatigue, adaptation and memory effects. Using Thurstonian analysis, we quantify this reduction in effect size and we apply a recently developed guideline to show that the Tetrad test remains more powerful than the Triangle test in this setting, even with the reduction in effect size.PRACTICAL APPLICATIONSThis paper demonstrates that the Tetrad test is a superior alternative to the Triangle test in at least one practical setting. More generally, this paper serves as a template for sensory researchers who might replace Triangle testing with Tetrad testing within their discrimination testing programs. Using the analytic methods outlined in this paper, researchers can quantify the increase in perceptual noise caused by the addition of a fourth stimulus.