Research Article

Study of Query Expansion Techniques and Their Application in the Biomedical Information Retrieval

Table 4

Accuracy of query search using different stemming functions and stopword lists in Cystic Fibrosis. Evaluation measures used are MAP (mean average precision), R-prec (R precision), and (number of relevant documents retrieved).

Combinations Measures
MAP R-prec

Baseline 0.1545 0.2098 683
Porter stemmer 0.1663 0.2154 747
Krovetz stemmer 0.1663 0.2231 740
NLM stopword list 0.1681 0.2242 723
SMART stopword list 0.1695 0.2243 728
Porter stemmer-NLM stopwords 0.17900.2332786
Porter stemmer-SMART stopwords0.18080.2342790
Krovetz stemmer-NLM stopwords 0.17990.2333782
Krovetz stemmer-SMART stopwords 0.18080.2324786

The bold font refers to the best values for the parameters.