EXPRESS: The Power of a Star Rating: Differential Effects of Customer Rating Formats on Magnitude Perceptions and Consumer Reactions

Average product ratings are displayed on many major websites, including online retailers, search engines, and social media sites. Research in both academia and industry has shown that consumers rely heavily on product ratings when making purchase decisions. Websites may show customer ratings in different shapes, colors, or formats. For example, some websites present their rating in a numerical format (e.g., 4.0/5) while others utilize an analog format (e.g., êêêêê). The present research investigates how a website’s rating presentation may influence magnitude perceptions of the rating, which subsequently affect choices and purchase intentions. We propose and find that when the average customer rating is at or above the midpoint (i.e., .5 - .9) of each rating level (i.e., 1 – 5 on a 5-pt. scale) the numerical (vs. analog) rating format is perceived to be lower in magnitude due to left-digit anchoring, leading to differences in choice likelihood, purchase intent, and ad click likelihood for products and services. Across nine experiments, including an eye tracking study, and a multiple-ad study without holdout, we show robust evidence for our proposed effect.