Effect of Expansion and Reformulation of Query on Improved Precision of Retrieval Results

Expansion and reformulation of queries are among the most common strategies employed by users in retrieval of initial results to coordinate them with their needs. The present study examines the expansion and reformulation of queries and their impact on improving the precisionof the retrieval results.The analytical survey method was used to evaluate the relationship between the variables. The study was conducted on the MA students of the Information Science and Knowledgein Islamic Azad University of Ahvaz, Khuzestan Science and Research Branch, who had the seminar course(n=28). The data were collected using a researcher-made questionnaire. The results showed the lack of enough time to review all the retrieved results as the most important reason for the expansion and reformulation of queries (mean = 4.66). In addition, the users reported different perceived usefulness of the expansion and reformulation tools for the retrieval results where they perceived the reformulation strategy more useful (mean =3.781). Furthermore, the precision of the initial results was significantly increased using the reformulation tools. The tools including limiting the search terms by the resource title, subject, year, and searching the initial results enhance the overall precision of the initial results. However, for the expansion tools, using these limiting approaches resulted in no significant difference between the precision of initial results and the final retrieval results. The results show that using the expansion and reformulation tools to correct the initial search may have different reasons. Moreover, the use of these tools affects the precision of searches.