A hybrid search engine
is a computer program
designed to help one find and sort information stored on a network by using three or more separate bodies of metadata in terms of an algorithimic process. The term, HSE, itself is still being defined, and some would argue that many of the leading search engines are technically HSEs due to the fact they include ranking algorithms based upon a combination of factors such as (1) hyperlink references to a given web page (i.e., how many other sites link to a page), (2) hyperlink execution history (i.e., how often people click to open a particular link), and (3) metadata derived from a web crawler (i.e, a complete index of all websites).
A hybrid search engine differs from traditional text oriented search engines such as Google or a directory-based search engine such as Yahoo! in which each program operates by comparing a set of metadata, the primary corpus being the metadata derived from a web crawler or taxonomic analysis of all internet text, and a user search query. In contrast, an HSE may use these two bodies of metadata in addition to one or more sets of metadata that can, for example, include situational metadata derived from the client's network that would model the context awareness of the client.