Searching for patterns in the MeSH vocabulary

NLM revises its MeSH vocabulary annually to reflect changes in biomedical literature and the health sciences community. This study tested two hypotheses about NLM's MeSH vocabulary. The first is that new terms are added to MeSH when their broader terms have an increased number of postings. One examination compared the number of postings for the broader terms of new and existing terms in the current MEDLINE file; the other compared them over time. No significant statistical difference was found in either case. A second hypothesis--that there is a relationship between the patterns of MEDLINE indexing and searching and the organization of the MeSH tree structure--was tested by comparing the distribution of searched terms in the MeSH trees with the distribution of all terms. It was found that certain trees are searched more often than could be predicted by the overall term distribution, while others are searched less frequently than expected. In summary, (1) new terms cannot be predicted by the increase in postings of existing terms, and (2) searchers' and indexers' use of the terms' tree structure does not correlate with the terms' distribution in the MeSH trees.     

Searching for Solutions

Abstract

Lending services units at Indiana State University's Cunningham Memorial Library depend heavily on student employees to fulfill their specific missions. Problems attributed to poor communication and lack of motivation among student employees were causing negative impacts on the units' abilities to function well. To resolve these problems, supervisors established priorities, set goals, and conducted a literature search to identify optimum remedies. Solutions were chosen on the basis of cost and ease of implementation. Strategies adopted included recognizing out-standing students, formalizing peer training, improving communication through electronic posting, expanding training methods, and providing student employee manuals specific to each unit.     

Searching strategies for the Bulgarian language

This paper reports on the underlying IR problems encountered when indexing and searching with the Bulgarian language. For this language we propose a general light stemmer and demonstrate that it can be quite effective, producing significantly better MAP (around + 34%) than an approach not applying stemming. We implement the GL2 model derived from the Divergence from Randomness paradigm and find its retrieval effectiveness better than other probabilistic, vector-space and language models. The resulting MAP is found to be about 50% better than the classical tf idf approach. Moreover, increasing the query size enhances the MAP by around 10% (from T to TD). In order to compare the retrieval effectiveness of our suggested stopword list and the light stemmer developed for the Bulgarian language, we conduct a set of experiments on another stopword list and also a more complex and aggressive stemmer. Results tend to indicate that there is no statistically significant difference between these variants and our suggested approach. This paper evaluates other indexing strategies such as 4-gram indexing and indexing based on the automatic decompounding of compound words. Finally, we analyze certain queries to discover why we obtained poor results, when indexing Bulgarian documents using the suggested word-based approach.     

Searching for the evidence using PubMed

This article discusses practical methods of searching for the evidence using PubMed. Four searching techniques are included: Simple Limit, Preview/Index, Clinical Queries, and the MeSH Browser. Search strings based on the University of Rochester's Clinical Filters are provided.     

寻找被遗忘的王朝

近日来，随着中外媒体不断报道，号称“东方金字塔”的西夏王陵，再次引起世人注目。尤其神秘王陵被发现的经过，那个“谜一样的王朝”在历史上的消失，及西夏后裔今天的情况等，更引起人们的浓厚兴趣。为弄清隐藏在这条新闻背后的一系列“热点”问题，日前记者循着王朝遗迹，在原西夏都城“兴庆府”故地进行了追踪采访，试图揭开“冰山一角”。　　西夏王陵偶然被中国军人发现，有关专家无不为之震动：其规模竟与河南宋陵、北京明十三陵相当，且在中古时期的丧葬文化史上独树一帜！　　关于西夏帝陵的记载最早见于《宋史·夏国传》，但仅记…     

Ｗeb检索与联机检索

介绍了部分专业检索人员对Ｗeb检索与联机检索的看法、以及一项善于联机与Ｗeb搜索引擎两者检索效果的对比笥研究，鉴于目前大量传统的收费情报可通过Ｗeb免费获取，作者着重讨论了如何在Ｗeb上免费检索各类传统情报，并指出Ｗeb免费检索传统情报对联机检索带来的冲击。     

网络课件检索机制

从网络课件检索的几个相关概念入手，介绍了几种检索技术，并根据网络课件的特点在教育资源管理系统(ERMS)中采用了几种相关的检索机制，并对未来检索机制发展的趋势做了一个简单分析。