Relevance and ranking in online dating systems pdf
Most IR systems compute a numeric score on how well each object in the database matches the query, and rank the objects according to this value.
The top ranking objects are then shown to the user.
An object is an entity that is represented by information in a content collection or database.
User queries are matched against the database information.
The process may then be iterated if the user wishes to refine the query.there is ... whereby letters and figures are coded as a pattern of magnetic spots on a long steel tape.
By this means the text of a document, preceded by its subject code symbol, ca be recorded ... automatically selects and types out those references which have been coded in any desired way at a rate of 120 words a minute detailing an early mention of the Univac computer.
An information retrieval process begins when a user enters a query into the system.
This ranking of results is a key difference of information retrieval searching compared to database searching. Often the documents themselves are not kept or stored directly in the IR system, but are instead represented in the system by document surrogates or metadata.
Virtually all modern evaluation metrics (e.g., mean average precision, discounted cumulative gain) are designed for ranked retrieval without any explicit rank cutoff, taking into account the relative order of the documents retrieved by the search engines and giving more weight to documents returned at higher ranks.
In binary classification, precision is analogous to positive predictive value.
In 1992, the US Department of Defense along with the National Institute of Standards and Technology (NIST), cosponsored the Text Retrieval Conference (TREC) as part of the TIPSTER text program.
The aim of this was to look into the information retrieval community by supplying the infrastructure that was needed for evaluation of text retrieval methodologies on a very large text collection.