How the overlap between the search results of different retrieval systems correlates with document relevance
Anselm Spoerri · Proceedings of the American Society for Information Science and Technology · 2005
Abstract This paper provides an analysis of the overlap between the search results of retrieval systems that participated in TREC 3, 6, 7 and 8 to provide empirical support for some of the key assumptions guiding the design of data fusion methods. It shows that the potential relevance of a document increases exponentially as the number of search methods retrieving it increases — called the Authority Effect. It also shows that documents higher up in ranked lists and found by more systems are more likely to be relevant — called the Ranking Effect. Both effects can help explain why major data fusion methods perform well.