Skip to content  How to combine multiple notions of relevance in
search?  by Michael Nielsen on February 4, 2012  In earlier
posts I’ve described two different ways we can assess how
relevant a given webpage is to a search query: (1) the cosine
similarity measure; and (2) the PageRank, which is a query-
independent measure of the importance of a page. While it’s good
that we have multiple insights into what makes a webpage
relevant, it also gives rise to a problem: how should we combine
these two measures to determine the ranking of a particular
webpage for a particular search query?  In fact, in practice the
problem gets much more complex than this, because there are more
than two useful notions of search relevance. For instance, we’d
surely also wish to incorporate a relevance measure that
quantifies how likely or unlikely a given page is to be spam. By
doing that we could ensure that pages which are likely to be
spam receive a much lower ranking. We might also wish to
incorporate a measure which ranks a pag