Consistency of expert product reviews: an application to wine guides

Purpose. Th e purpose of this study is to examine the internal consistency of wine guides by comparing the judgements of expert wine tasters and reviewers. A classifi cation of wines is provided to establish whether expert reviews of similar wines are coherent. Design/methodology/approach. Sentiment analysis based on natural language processing techniques was used to compare quantitative and qualitative reviews between experts. In addition, a fi nite mixture model was used to classify wines into categories to analyse internal consistency between ratings. Findings. Th e results for a sample of more than 200,000 Wine Enthusiast ratings reveal signifi cant diff erences between expert reviews. Th is fi nding indicates that there are no standard criteria for reviewing wines included in the guide. Originality. Wine guides are amongst the most widely used marketing resources in the wine industry. Th ey provide a signal to consumers about the quality of wines, guiding their purchase decisions. Th ey also infl uence the reputation of brands and the performance of companies producing these wines.