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Меры релевантности строка-текст в проблеме рубрикации научных статей
Many semantic text analysis problems employ string-to-text relevance measures. Research paper annotation problem is no exception. In general, research papers are annotated according to a system of topics, organized as a taxonomy, a hierarchy of topics (or concepts). For example the papers, published in journals of the international Association of Computing Machinery (ACM), the most influential organization in the Computer Science world, are annotated according to the Computing Classification System taxonomy (ACM CCS).
String-to-text relevance measures should be used to automate the research paper annotation procedure since taxonomy topics are strings ant research papers or any of their constituents are texts. A relevance measure maps a string–text pair to a real number. The meaning of the mapping depends on the relevance model under consideration. Under any model, the higher the relevance value, the stronger the association between the string and the text.
This paper explores the use of phrase-to-text relevance measures to annotate research papers in Computer Science by key phrases taken from the ACM Computing Classification System. Three phrase-to-text relevance measures are experimentally compared in this setting. The measures are: (a) cosine relevance score between conventional vector space representations of the texts coded with tf-idf weighting; (b) a popular characteristic of the probability of “elite” term generation BM25; and (c) a characteristic of the symbol conditional probability averaged over matching fragments in suffix trees representing texts and phrases, CPAMF, introduced by the authors. Our experiment is conducted over a set of texts published in journals of the ACM and manually annotated by their authors using topics from the ACM CCS. Applying any of the relevance measures to an article results in a list of taxonomy topics sorted in the descending order of their relevance values. The results are evaluated by comparing these sorted lists and lists of topics assigned to articles manually. The higher a manually assigned topic is placed in a relevance based sorted list of topics, the more accurate the sorted list is. The accuracy of the computational annotations is scored by using three different scoring functions: a) MAP, b) nDCG, c) Intersection at k, where (a) and (b) are taken from the literature, and (c) is introduced by the authors. It appears, CPAMF outperforms both the cosine measure and BM25 by a wide margin over all three scoring functions.