Thesis (Ph.D.)--Indiana University, School of Library and Information Science, 2006. / Adviser: Elin K. Jacob.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007. / Source: Dissertation Abstracts International, Volume: 68-11, Section: A, page: 4528. Adviser: Boyd Rayward. Includes bibliographical references (leaves 264-279) Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007. / Source: Dissertation Abstracts International, Volume: 68-11, Section: A, page: 4528. Adviser: Linda C. Smith. Includes bibliographical references (leaves 191-205) Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2009. / Source: Dissertation Abstracts International, Volume: 70-06, Section: A, page: . Adviser: Ann Bishop. Includes bibliographical references (leaves 176-184) Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph. D.)--Texas Woman's University, 1989. / Abstract. Includes bibliographical references.

Thesis (Ph. D.)--Texas Woman's University, 1989. / Abstract. Includes bibliographical references.

Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 1996. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 145-168).

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 67-07, Section: A, page: 2366. Adviser: Les Gasser. Includes bibliographical references (leaves 243-257) Available on microfilm from Pro Quest Information and Learning.

The overall objective of this study is to analyze the document retrieval process and the main information retrieval (IR) concepts from the point of view of semiotics and design retrieval mechanisms based on the findings of the semiotic analysis of the retrieval situation. Semiotics is a discipline which studies 'sign systems' and how signs are exchanged in communication. The semiotic view of IR interaction presented in this dissertation views document retrieval as a kind of human communication process taking place in a social and cultural realm. The most important result of the semiotic model developed is the explication of the distinction between the knowledge production and transfer functions of document retrieval. The consequence of this finding is the conceptualization of the retrieval process as a dynamic and complex interplay between knowledge production and transfer tasks. It is hypothesised that, in the case of knowledge production, users of retrieval systems are interested in exploring new areas of the document collection which are not a priori known. Two knowledge based systems are developed based on the Okapi probabilistic retrieval system. The purpose of the retrieval systems designed is posited, in general terms, as to suggest the users new search areas of potential interest. This is achieved by treating the Inspec thesaurus as a semantic network, and applying a heuristic spreading activation technique to generate clusters of terms linked in the Inspec thesaurus. Each cluster or batch of terms is conceived as representing a part of the general search area defined by the initial user search terms. The main design objective here is to enable the user to identify new search areas from the term information contained in the batches. Two evaluation experiments were carried out with real users who had real information needs to test whether the batches were actually effective in defining search areas related to the original user queries and whether they were useful in pointing new areas which were potentially relevant to the users. A number of hypotheses related to the retrieval effectiveness of the knowledge based systems designed were also tested in the experiments. The main findings of the experiments indicate that: • the batches were useful in representing search domains relevant to the users' queries • in many cases the batches represented new ideas or new search domains to the users • the knowledge based systems had similar retrieval effectiveness in terms of precision as the Okapi system.

Evaluation studies can help libraries to find out their strengths and weaknesses and use this knowledge for re-orienting their collections, services and facilities to effectively meet the information needs of their users. The purpose of this study was to explore the information needs and seeking behaviour of agricultural scientists in Malaysia and how effectively their needs are satisfied by their libraries. The study investigated some major factors that were considered important in effectively meeting the information needs of these scientists. Five major agricultural institutions in Malaysia participated in the study. Data was collected through two questionnaires and follow-up interviews with selected respondents and library staff. The user survey questionnaire provided data on information needs and seeking behaviour of respondents, their assessment about the adequacy of library collections, services and facilities, and their overall perceptions about library effectiveness. The library survey questionnaire furnished data from the participating libraries on their manpower, budget, collections, physical resources, library services, and resource sharing activities. The population of the study comprised 1,328 individuals. Proportionate stratified random sampling technique was used to generate random samples. A total of 332 questionnaires were distributed and 234 useable questionnaires were received back with an overall response rate of 70.5 percent. The study found that research and review articles were the most preferred sources for getting up-to-date information. Interaction . with professional colleagues was also considered important for information exchange. Libraries were more extensively used during two important stages of research, i.e., proposal development and report writing. Although a majority of the respondents personally visited their library they, however, sent their junior researchers andlor para-professionals for getting photocopies of articles, checking out books or getting information from the sources already known to them. The use of IT-based information sources and facilities was very low, although a majority of the respondents possessed reasonably good computing skills. Among the Internet applications, e-mail was the most popular while other Internet-based sources and facilities were used infrequently. A positive relationship was found between perceptions about library effectiveness and assessment of participants of the adequacy of library collections, equipment and physical resources. Other factors having a positive impact on the perception about library effectiveness were: involvement in the selection of library materials; notification of current materials; adequate promotion; convenient library location; staff attitude; and participation in user education programmes. The level of resource sharing among Malaysian libraries was quite high as nearly 74 percent of the interlibrary loan and document delivery requests of the participating libraries were met locally. However, only a minimal resource sharing was found among the participating libraries and libraries in the ASEAN countries. Although the participating libraries agreed in principle to participate in a resource sharing scheme, they felt that it should be the prerogative of the participating library to decide its level of co-operation and with which library to share its resources. It means that these libraries were in favour of a "loose" library co-operation network. A big difference was found between the number of document delivery requests made by these libraries to international sources and the number of such requests received by them from overseas, confirming one-way flow of information. Most of the document delivery requests were made to the BLDSC. Malaysian agricultural scientists, as compared to scientists in developed countries, made considerably less number of interlibrary loan and document delivery requests. A positive relationship was found between the availability of funds in research projects for literature procurement and the number of document delivery requests made. The study concludes that agricultural libraries in Malaysia were to some extent meeting the information needs of their scientists, although a disparity among these libraries was quite evident. However, the financial crisis of 1997 has severely affected the performance of these libraries. Library collections, services and facilities considered reasonable at the time of this study may quickly become inadequate due to the lack of funds to sustain them. Therefore, agricultural libraries in Malaysia need to develop appropriate strategies for surviving in the rapidly changing environment. Major recommendations of the study are: development of a formal resource sharing scheme for agricultural libraries in Malaysia, putting holdings information of these libraries on the Internet to facilitate resource sharing, making subscriptions to full-text electronic journals, more library co-operation among ASEAN countries, and the conduct of intensive user education programmes.