The Scale Effect: How Rating Scales Affect Product Evaluation
(A2021-94343)

AUTHORS

Rahil Hosseini, Pompeu Fabra University; Gaël Le Mens, Pompeu Fabra University

ABSTRACT

Products are frequently reviewed on several websites that rely on different scales, for example, a 5-point scale (Amazon.com) and a 100-point scale (Consumer Reports). How do consumers aggregate these ratings as they form purchase intentions and make consumption decisions? We consider a setting in which a consumer evaluates products based on two rating scores on different scales. Across 7 studies (N = 2391), we found that ratings expressed on larger scales have a stronger effect on product evaluations than ratings expressed on smaller scales. We call this phenomenon the ‘scale effect.’ This effect results from differences in perceived informativeness: ratings expressed on larger scales are perceived as more informative of product quality than ratings expressed on smaller scales. By contrast to prior research on the effect of attribute scales (rather than ratings) on product evaluations, we did not find that rating numerosity explain the scale effect.