Is Relevance Relevant? User Relevance Ratings May Not Predict the Impact of Internet Search on Decision Outcomes

User provided relevance rankings taken in isolation seem to be of limited to no value when designing a search engine that will be used in a general-purpose setting. Relevance rankings may have a place in situations in which experts provide rankings, and decision tasks are of complexity commensurate with the abilities of the raters. A more natural metric of search engine performance may be a user's ability to accurately complete a task, as this removes the inherent subjectivity of relevance rankings, and provides a direct and repeatable outcome measure which directly correlates with the performance of the search technology in the hands of users.