A Brief History of Search Results Ranking.

The theory and practice of search results ranking, as currently offered by most web search engines, is older than one might think. The first proposal for a system of ranking was in a JACM paper in 1960. Through the remainder of the twentieth century, extensive research work was done on ranking systems—on devising methods of ranking, on the use of learning methods in association with ranking, and on the comparative evaluation of alternative methods. The web search engines of the tail end of the century made much use of this paper. [ABSTRACT FROM AUTHOR]