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Pii0 is ok i pij j 4 introducon to informaon retrieval

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Unformatted text preview: Random walk can get stuck in dead ­ends.   Makes no sense to talk about long ­term visit rates.   With remaining probability (90%), go out on a random link.   10%  ­ a parameter. ?? Introduc)on to Informa)on Retrieval Sec. 21.2 Introduc)on to Informa)on Retrieval S ec. 21.2.1 Result of telepor*ng Markov chains   Now cannot get stuck locally.   There is a long ­term rate at which any page is visited (not obvious, will show this).   How do we compute this visit rate?   A Markov chain consists of n states, plus an n×n transi*on probability matrix P.   At each step, we are in exactly one of the states.   For 1 ≤ i,j ≤ n, the matrix entry Pij tells us the probability of j being the next state, given we are currently in state i. Pii>0 is OK. i Pij j 4 Introduc)on to Informa)on Retrieval Sec. 21.2.1 Markov ch...
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