lecture17-linkanalysis-handout-6-per

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Unformatted text preview: te in matrix form   View the hub scores h() and the authority scores a() as vectors with n components.   Recall the itera*ve updates   h=Aa.   a=Ath. S ec. 21.3 Substituting, h=AAth and a=AtAa. Thus, h is an eigenvector of AAt and a is an eigenvector of AtA. h( x ) ← ∑ a ( y ) x y Further, our algorithm is a particular, known algorithm for computing eigenvectors: the power iteration method. a ( x ) ← ∑ h( y ) y x Introduc)on to Informa)on Retrieval Recall At is the transpose of A. Guaranteed to converge. Sec. 21.3 Issues   Topic Dril Connec*vity servers   Off ­topic pages can cause off ­topic authori*es to be returned   E.g., the neighborhood graph can be about a super topic   Mutually Reinforcing Affiliates   Affiliated pages/sites can boost each others scores   Linkage between affiliated pages is not a useful signal 8 Introduc)on to Informa)on Retrieval Sec. 20.4 Connec*vity Server Introduc)on to Informa)on Retriev...
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This document was uploaded on 02/26/2014.

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