Definition
For a given query topic Q, R-precision is the precision at R, where R is the number of relevant documents for Q. In other words, if there are r relevant documents among the top-R retrieved documents, then R-precision is \({r}\over{R}\).
Key Points
R-precision is defined as the proportion of the top-R retrieved documents that are relevant, where R is the number of relevant documents for the current query. This requires full knowledge of a query’s relevant set, and will be a shallow evaluation for a query with few relevant documents and a deep evaluation for a query with many relevant documents. Rank cutoff R is the point at which precision and recall are equal, since at that point both are \({r}\over{R}\).
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© 2009 Springer Science+Business Media, LLC
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Craswell, N. (2009). R-Precision. In: LIU, L., ÖZSU, M.T. (eds) Encyclopedia of Database Systems. Springer, Boston, MA. https://doi.org/10.1007/978-0-387-39940-9_486
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DOI: https://doi.org/10.1007/978-0-387-39940-9_486
Publisher Name: Springer, Boston, MA
Print ISBN: 978-0-387-35544-3
Online ISBN: 978-0-387-39940-9
eBook Packages: Computer ScienceReference Module Computer Science and Engineering