In this paper, we investigate the difference between Wikipedia and Web link structure with respect to their value as indicators of the relevance of a page for a given topic of request. Our experimental evidence is from two IR test-collections: the .GOV collection used at the TREC Web tracks and the Wikipedia XML Corpus used at INEX. We first perform a comparative analysis of Wikipedia and .GOV link structure and then investigate the value of link evidence for improving search on Wikipedia and

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... the .GOV domain. Our main findings are: First, Wikipedia link structure is similar to the Web, but more densely linked. Second, Wikipedia's outlinks behave similar to inlinks and both are good indicators of relevance, whereas on the Web the inlinks are more important. Third, when incorporating link evidence in the retrieval model, for Wikipedia the global link evidence fails and we have to take the local context into account.