June 9th, 2007 by 
Session based personalization – understanding user intent based on queries & clicks – when does session get started? Interest based personalization – understanding user interest based upon declared preferences or user behavior inside or outside search context. Challenge – users sometimes do searches outside their area of interest / normal behavior. Queries should get shorter, more of the top ten should be relevant to the user so long as correct user intent is extrapolated. Impact: Better matching, give search engines enough content on page to help determine topicality. Yahoo’s approach – user activity in social products, help them discover content interesting to them and their community. Recovery applications can help save site, i.e. “refind” information that you’ve already found.
