1. A computer system for calculating importance of pages, comprising: a data store that contains references to each page; and a processor that performs the processing of a calculate importance component that calculates the importance of pages factoring in importance of sites that contain the pages and importance of linked-to pages wherein the transition probability is represented by the following equation: p ⁡ ( i → j | s ⁡ ( j ) ) = f ⁡ ( i → j | s ⁡ ( j ) ) ∑ k ⁢ f ⁡ ( i → k | s ⁡ ( k ) ) where p(i→f |s(f)) is the conditional probability of transitioning from page i to page f when page j is in site s(j), k represents a page in site s(j), and f(i→j|s(f)) represents the frequency corresponding to the probability under a random surfer model of transitioning from page i to page j adjusted by a correlation of the importance of the site to the importance of the page and by the importance of the site.