Comparing central location test and home use test results: Application of a new criterion Isabelle Boutrolle a,b, * , Delphine Arranz a , Michel Rogeaux a , Julien Delarue b a Sensovaleur—Perceptions et Pre ´fe ´rences, Danone Vitapole, RD 128, 91767 Palaiseau Cedex, France b Laboratoire de Perception Sensorielle et Sensome ´trie, UMR SCALE (ENSIA-CNAM-INRA), 1 Avenue des Olympiades, 91744 Massy Cedex, France Received 23 June 2004; accepted 29 March 2005 Available online 28 June 2005 Abstract Choosing a consumer test methodology is critical for any company sensory scientist. However, we lack tools for comparing the outcome of consumer tests. Here we intended to develop a new comparison criterion based on a concept borrowed from metrology: robustness. We tested this concept with hedonic ratings data obtained from a central location test (CLT) on one hand and from a home use test (HUT) on the other hand. Two fermented milk beverages were tested and both tests were conducted with 240 subjects. The beverages differed in fat and sugar content. The comparison of the CLT and HUT data sets (both in monadic sequential) indi- cates that the method has a significant effect on the degree of liking. Indeed, the liking scores are lower with CLT than with HUT. Still, both tests lead to the same conclusion that the product with the higher fat and sugar content is significantly more liked. Besides, we developed three graphic representations that illustrate the results stability faced with the decrease in the panel size. These graphs show that CLT yields more robust results than HUT. Additionally the leading role of the panel size is emphasised for both tests. Our data show that the results from the two methods may change as soon as 20 subjects are removed from our original data set. These results that were not unexpected illustrate a fact which is often underestimated in practice. Ó 2005 Elsevier Ltd. All rights reserved. Keywords: Liking; Hedonic scores; Central location test; Home use test; Robustness; Panel size 1. Introduction The main concern of food industry is to fulfil con- sumer needs. It is thus crucial for the food industry to ex- plore and to understand consumer preferences. Together with the marketing services, the corporate sensory teams aim at measuring these consumer preferences. The hedo- nic tests carried out by sensory analysts aim at assessing the product sensory acceptability. Among various possibilities, the central location test (CLT) is the most frequently used sensory acceptance test. It usually takes place in a standardised room in order to control the conditions of evaluation. Subjects are interviewed individually and they express their opin- ion about the tasted products. These products are usually free of any non-sensory external factors such as packaging, brand, price and so on. However, these conditions are somehow artificial (i.e. different from a natural consumption situation). Therefore, the relevance of CLT data is sometimes discussed (Meiselman, 1992). Besides, the experimenter can use other test methodo- logies such as the home use test (HUT). Indeed, pre- paration and use may be of prime importance in the appreciation of food products in the home environment. 0950-3293/$ - see front matter Ó 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodqual.2005.03.015 * Corresponding author. Address: Sensovaleur—Perceptions et Pre ´fe ´rences, Danone Vitapole, RD 128, 91767 Palaiseau Cedex, France. E-mail address: isabelle.boutrolle@danone.com (I. Boutrolle). www.elsevier.com/locate/foodqual Food Quality and Preference 16 (2005) 704–713