Product Label List Format: Effects of Item Arrangement and Completeness on Comparison Time and Accuracy

Abstract

This research examined the influence of two factors on the ease of gaining information from item lists: the order and completeness of the items displayed. Food nutrition labels served as the vehicle to test the manipulated lists on comparison time and accuracy performance measures. Four booklets, each containing 12 pairs of nutrient labels, were constructed in which the listed items were: (1) either arranged in a standard order or in a random order, and (2) either had a complete set of nutrients (including nutrients not present in the product) or a partial set of nutrients (excluding nutrients with zero or near-zero amounts in the product). Thirty-two participants were instructed to assume that their physician has told them to increase their intake of three specific nutrients and decrease their intake of three other nutrients. One label of each pair contained a higher level of one nutrient that should be increased or a lower level of one nutrient that should be decreased. Participants were to determine which of the two labels would be better given the prescribed diet. Time and accuracy measures were collected. Participants made significantly faster judgments for nutrients arranged in a standard order than for nutrients arranged in a random order. For all conditions, the error rate was low. An interaction indicated that labels with a complete set of nutrients in a standard order produced fewer errors than (a) labels in a standard order with some nutrients missing or (b) labels with a complete set of nutrients in a random order. Implications of making lists compatible with expectations are described.