6533b7d5fe1ef96bd1263e29

RESEARCH PRODUCT

Uses of change-over designs and repeated measurements in sensory and consumer studies

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Abstract The paper illustrates two statistical methods, the design and analysis of sensory experiments taking into account the effects of serving order and previously assessed treatment and the analysis of experiments with time repeated measurements. Change-over design experiments balance both presentation order and carry-over effects. The proper analysis of variance allows the testing of these effects and the estimation of product means adjusted for carry-over effect. Repeated measurements occur when groups are being compared over time. Either a corrected split-plot or a multivariate analysis of variance (MANOVA) with measurements at different times forming the variable should be adopted to allow proper tests for the time effect and for its interaction with the group effect. The usefulness of change-over designs with an appropriate analysis and repeated measurement analysis will be demonstrated using sensory experiments involving trained assessors and consumers.