Google Gets Personal
The basic principle behind personalized search is simple. When you go to Google and type in a search query, Google stores the data. As you return to the engine, a profile of your search habits is built up over time. With this information, Google can understand more about your interests and serve up more relevant search results. For instance, let’s say that you have shown an interest in the topic of sport fishing in your search queries, while your neighbor has shown an interest in musical instruments in his search queries. Over time, as these preferences are made clear to the engine, your personalized search results for the term “bass” will largely be comprised of results that cover the fish while your neighbor’s results for “bass” will be comprised of results that primarily cover the musical instrument.
At present, you need to have signed up for a Google service for your results to be personalized. Such services include Gmail, AdWords, Google Toolbar, and many others. By default, as long as you are signed in to one of these programs, your personal search data will be collected. The term “at present” is used because Google certainly could implement personalized search on any user of the engine, regardless of whether he or she has a Google account. Google already places a cookie, or unique identifier, on the machine of anyone who types in a search query on Google - it would not be hard for them to use that information, rather than the Google account, to collect individual user data and personalize results. It is quite possible that Google is testing the waters of personalized search with people who have opted in to one of its services and will expand the system to all users if there is limited uproar or government intervention.
Unless the government intervenes, the question will probably be decided by personal preference. As it becomes more common knowledge that Google (and other engines) store this type of data to enable personalized search, many users will take measures to block its use.
Is this an invasion of personal information?? It looks like only time will tell.