سوال ۱۷ کنکور ارشد مهندسی کامپیوتر ۱۴۰۱

PASSAGE 1 (excerpt): When a user enters a query into a search engine (typically by typing keywords), the engine examines its index and provides a listing of best-matching web pages according to its criteria, usually with a short summary containing the document's title and sometimes parts of the text. The index is built from the information stored and the method by which the information is indexed. The usefulness of a search engine depends on the relevance of the results set it gives back. ... A search engine decides which pages are the best matches and ranks the results to list the “best” results first. ... Many search engines, such as Google and Bing provide customized results based on the user's activity history. This leads to an effect that is called a filter bubble. ... websites tend to show only information that agrees with the user's past viewpoint, effectively isolating the user in a bubble that tends to exclude contrary information.

Question: All of the following are the main jobs of search engines EXCEPT ----------.