Ask.com answers questions by culling details from expert knowledge. Teoma, or ExpertRank, is the name of the algorithm that Ask.com uses to gather online information from highly respected, authoritative sources.
Like any algorithm, ExpertRank goes through a series of steps in order to solve a problem or perform a function. Which algorithmic steps are unique to ExpertRank is unclear based upon the current literature, as of 2015. How ExpertRank defines expert sources is slightly less mysterious.
An authoritative source is one that points to many good hubs, or Web pages. A good hub is a page that points to many authoritative sources. ExpertRank, a mini search engine unto itself, evaluates potential authorities and hubs based upon their mutually reinforcing paradigm.
ExpertRank only considers sources that possess subject-specific popularity among topic clusters and innumerable Web pages by experts commenting on the topic. The results include a handful of authoritative sources whose words on a subject constitute an expert answer. Ask.com, which still goes by its former name, Ask Jeeves, in the United Kingdom, does not specify who transforms the gathered knowledge into the actual answers to questions that appear on its website.
Ask.com was once a search engine in addition to a question-answer search engine. Ask.com abandoned the search industry in 2010. The Ask.com search engine also relied upon the ExpertRank algorithm to provide results to search queries.