Transparency in Keyword Faceted Search: An Investigation on Google Shopping

The most popular e-commerce search engines allow the user to run a keyword search, to find relevant results and to narrow down the results by mean of filters. The engines can also keep track of data and activities of the users, to provide personalized content, thus filtering automatically out a part of the results. Issues occur when personalization is not transparent and interferes with the user choices. Indeed, it has been noticed that, in some cases, a different ordering of search results is shown to different users. This becomes particularly critical when search results are associated with prices. Changing the order of search results according to prices is known as price steering. This study investigates if and how price steering exists, considering queries on Google Shopping by users searching from different geographic locations, distinguishable by their values of Gross Domestic Product.

The results confirm that products belonging to specific categories (e.g., electronic devices and apparel) are shown to users according to different prices orderings, and the prices in the results list differ, on average, in a way that depends on users’ location. All results are validated through statistical tests.