How Does Google Collect and Rank Results?by Kent Lewis on January 13, 2006Uncategorized
Matt Cutts discusses how Google crawls, indexes and ranks search results in Google’s Newsletter for Librarians. The article notes that when crawling and indexing, Google “asks a web server to return a specified web page, and then scans that web page for hyperlinks, which provide new documents that are fetched the same way”. Each page is given a number and added to its index so it can be referenced to when the pages are checked for relevancy. Once the index is built, Google uses hundreds of computers to find the set of pages that contains the user’s query by selecting the document numbers where the individual query terms intersect in an index (Cutts provides a visual example in his article). After the relevant pages are selected, Google ranks the pages based on PageRank, reputation, proximity of keywords and page title. The results are then displayed by relevance in the search engine results page.