Research Article
Study of Query Expansion Techniques and Their Application in the Biomedical Information Retrieval
Table 6
MAP values for the TF-IDF BM25, Raw TF, and
formulas.
| Combinations | Parameters | | | | | | | | | | Raw TF | | 1.2 | 0.75 | 1000 | 1.3 | 0.6 | 1.2 | 1.2 | 0.7 | 1.2 |
| Porter stemmer-NLM stopwords | 0.1861 | 0.1868 | 0.1861 | 0.1422 | 0.1749 | Porter stemmer-SMART stopwords | 0.1866 | 0.1898 | 0.1878 | 0.1445 | 0.1742 | Krovetz stemmer-NLM stopwords | 0.1821 | 0.1843 | 0.1827 | 0.1420 | 0.1736 | Krovetz stemmer-SMART stopwords | 0.1828 | 0.1866 | 0.1839 | 0.1436 | 0.1731 |
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The bold font refers to the best values for the parameters.
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