The Four Quadrants of Personalization

Yesterday, The Mossberg Solution Column of the Wall Street Journal ran an article about Google’s SearchWiki and Surf Canyon. While we’ve released an update of our software to make sure that these two technologies are compatible and have discussed how they compliment each other, it’s perhaps worth positioning these technologies in a larger framework of search personalization.

Personalization is often been divided into two categories, implicit and explicit, the respective merits of which have been debated. Implicit personalization is based on preferences inferred from behavioral information. While this doesn’t require any effort on the part of the user, making accurate determinations of intent can be challenging. On the other hand, explicit personalization is driven by direct indication from the user. The intent is often clearer, however, the onus is on the user to make the effort to specify preferences.

Since April 2006, Surf Canyon has been looking at personalization from a different perspective: real-time vs. long-term. Real-time personalization alters the user experience instantly as behavioral signals are collected. While determining intent “on the fly” is challenging given the requirement for speed and the paucity of data, the signals are typically very strong. Long-term personalization, by contrast, relies on the accumulation of considerable user data over a significant amount of time. Determining the user’s “at the moment” intent can be difficult given how quickly the signals decay and how often users change context.

Nevertheless, as indicated here, all of these options are currently available to the internet searcher:

Surf Canyon v1 - Our flagship product introduced real-time implicit personalization for search. By observing the actions of the user as the search is taking place, the application helps people find information by re-ranking the results instantly, effectively transforming the search page from a static list of links to a dynamic set of results that “work with” the user.

Google Personalization - By observing the search pattern and click history of the user over an extended period of time, Google builds a profile of the user’s long-term interests which are then used to personalize the results for future searches. The first post on this blog analyzed some of the benefits and shortcomings of this technology.

Surf Canyon v2 - Launched in December ‘08, v2 of Surf Canyon introduced my.SurfCanyon.com, enabling users, should they so desire, to explicitly indicate sources of content they prefer as well as those that they dislike. These long-term preferences are then taken into account to, once again, personalize search results to the user’s benefit.

Google SearchWiki - Launched in November ‘08, SeachWiki offers controls to enable users to manually manipulate search results. By clicking a button, results may immediately be “promoted” to the top of the search page or deleted altogether. The next time the user runs the same search, the user’s personal modifications will be displayed.

Different users will have varying appreciations for the costs and benefits associated with each of these technologies, however, they are all compatible and, to a large extent, compliment each other. Today’s internet searchers are therefore free to use all of them, some of them or none of them, as they prefer.

Update (1/15/09) - Charles Knight at AltSearchEngines ran this post under their “Guest Authors” series.