Discrimination tests: Evaluating context effects and respondent reliability using the switchback experimental design

Abstract

As companies attempt the risky process of introducing new products and modifying existing ones, many engage in field experiments in which untrained volunteer respondents are used to assess product characteristics and preference. Because discrimination test designs currently employed by marketing researchers have inherent limitations and can independently lead to different results, examinations of other potentially useful design models is vitally important. This paper introduces the switchback experimental design to the marketing literature as an alternative research design for testing new products. The switchback design is recommended for product-testing situations where context effects and respondent reliability issues are anticipated. The design allows for measurement of the effect of product-testing order on a respondent's cognitive and affective judgments, and provides a direct measure of respondent judgment variability. This paper also presents the results of an empirical evaluation of the switchback design for a discrimination taste test. The switchback design promises more accurate feedback regarding both consumer product preference and discrimination, which should lead to better decisions on both new product development and product modification.© 2009 Palgrave Macmillan.