Srinivasan P
Department of Computer Science, Cornell University, Ithaca, NY, USA.
J Am Med Inform Assoc. 1996 Mar-Apr;3(2):157-67. doi: 10.1136/jamia.1996.96236284.
To investigate a new approach for query expansion based on retrieval feedback. The first objective in this study was to examine alternative query-expansion methods within the same retrieval-feedback framework. The three alternatives proposed are: expansion on the MeSH query field alone, expansion on the free-text field alone, and expansion on both the MeSH and the free-text fields. The second objective was to gain further understanding of retrieval feedback by examining possible dependencies on relevant documents during the feedback cycle.
Comparative study of retrieval effectiveness using the original unexpanded and the alternative expanded user queries on a MEDLINE test collection of 75 queries and 2,334 MEDLINE citations.
Retrieval effectivenesses of the original unexpanded and the alternative expanded queries were compared using 11-point-average precision scores (11-AvgP). These are averages of precision scores obtained at 11 standard recall points.
All three expansion strategies significantly improved the original queries in terms of retrieval effectiveness. Expansion on MeSH alone was equivalent to expansion on both MeSH and the free-text fields. Expansion on the free-text field alone improved the queries significantly less than did the other two strategies. The second part of the study indicated that retrieval-feedback-based expansion yields significant performance improvements independent of the availability of relevant documents for feedback information.
Retrieval feedback offers a robust procedure for query expansion that is most effective for MEDLINE when applied to the MeSH field.
研究一种基于检索反馈的查询扩展新方法。本研究的首要目标是在同一检索反馈框架内检验替代查询扩展方法。提出的三种替代方法为：仅在医学主题词（MeSH）查询字段上扩展、仅在自由文本字段上扩展以及在MeSH和自由文本字段上都扩展。第二个目标是通过检查反馈周期中对相关文档的可能依赖性，进一步了解检索反馈。
使用原始未扩展和替代扩展的用户查询，对包含75个查询和2334篇MEDLINE引文的MEDLINE测试集进行检索效果的比较研究。
使用11点平均精度得分（11-AvgP）比较原始未扩展和替代扩展查询的检索效果。这些是在11个标准召回点获得的精度得分的平均值。
所有三种扩展策略在检索效果方面均显著改善了原始查询。仅在MeSH上扩展等同于在MeSH和自由文本字段上都扩展。仅在自由文本字段上扩展对查询的改善明显小于其他两种策略。研究的第二部分表明，基于检索反馈的扩展在性能上有显著提升，且与用于反馈信息的相关文档的可用性无关。
检索反馈为查询扩展提供了一种强大的方法，当应用于MeSH字段时，对MEDLINE最为有效。
