Ruth Alexander believes that search engine accuracy depends on the computer and the copy of Google's search engine being used and whether or not they are personalized. There are several copies in the world, and it will depend on the version that is the least busy. She's convinced that search results are misleading, and tells us why. She points to Professor Mike Thelwall, a cybermetrics researcher at Wolverhampton University in the UK, who explains that "search engines could crawl the Internet forever and still not find all the Web pages that exist."