Synonyms
Inverse element frequency; Within-element term frequency
Definition
Classical ranking algorithms in information retrieval make use of term statistics, the most common (and basic) ones being within-document term frequency, tf, and document frequency, df. tf is the number of occurrences of a term in a document and is used to reflect how well a term captures the topic of a document, whereas df is the number of documents in which a term appears and is used to reflect how well a term discriminates between relevant and non-relevant documents. df is also commonly referred to as inverse document frequency, idf, since it is inversely related to the importance of a term. Both tf and idf are obtained at indexing time. Ranking algorithms for structured text retrieval, and more precisely XML retrieval, require similar terms statistics, but with respect to elements.
Key Points
To calculate term statistics for elements, one could simply replace documents by elements and calculate so-called...
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Clarke CLA. Controlling overlap in content-oriented XML retrieval. In: Proceedings of the 31st Annual International ACM SIGIR Conference on Research and Development in Information Retrieval; 2005. p. 441–48.
Grabs G, Schek H.-S. ETH Zürich at INEX: flexible information retrieval from XML with PowerDB-XML. In: Proceedings of the 1st International Workshop of the Initiative for the Evaluation of XML Retrieval; 2002. p. 141–8.
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Kamps, J., Lalmas, M. (2018). Term Statistics for Structured Text Retrieval. In: Liu, L., Özsu, M.T. (eds) Encyclopedia of Database Systems. Springer, New York, NY. https://doi.org/10.1007/978-1-4614-8265-9_412
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DOI: https://doi.org/10.1007/978-1-4614-8265-9_412
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