Methods of teaching on-line bibliographic searching: Experience at the College of Librarianship Wales

We have been teaching students about on-line bibliographic searching since 1972. With the help of British Library Research and Development Department funding we have recently extended our teaching in this area and now use services such as Lockheed, System Development Corporation and the British Library's BLAISE. This paper discusses aspects of the design of courses on on-line bibliographic searching, describes various methods we have used to demonstrate searches to students in order to prepare them for undertaking a live search themselves, and compares the relative costs, in terms of system costs and staff time, of these methods. The methods of demonstration involve the playing back of recorded searches on videotape, audio cassettes and digital cassettes as well as live demonstration and may be of interest to other teachers of library and information science students or to those involved in the training of people to carry out on-line bibliographic searching.     

MEDLINE: an introduction to on-line searching.

MEDLINE is presented as a prototype for on-line bibliographic search systems. Creation of the data base, indexing language, and file organization are reviewed. On accessing the files, search logic is illustrated with a sample MEDLINE search. NLM's development of a document delivery system to complement its bibliographic retrieval system is discussed.     

Hypertext vs boolean-based searching in a bibliographic database environment: A direct comparison of searcher performance

The purpose of this study is to carry out a direct comparison of a hypertext-based bibliographic retrieval system with a traditional Boolean-based retrieval system, each using the same database. Novice and experienced searchers were assigned to either a prototype hypertext system called HyperLynx or to a traditional Boolean system and were asked to perform a set of search tasks. The study revealed that the Boolean system performed better than the hypertext system for search tasks with a large number of relevant items. Searcher experience level did not play a significant role for either system. Findings of the study have implications for the design of future information retrieval systems that take advantage of the best features of both approaches for more effective and efficient retrieval of highly structured databases.     

Human information seeking: Online searching of bibliographic citation networks

The strategies, heuristics, and tradeoff?s involved in online searching of bibliographic citation networks are discussed. Results from the field of citation analysis are used to describe the mathematical structure of citation networks. An experimental environment called DBASE (Data Base Access and Search Environment) is discussed and its use in two studies of human information seeking behavior considered. Variables examined in these studies included the nature of the search question and the interconnectivity of the data base.     

Computer-aided searching of bibliographic data bases: Online estimation of the value of information

The study presents and synthesizes the results of a series of five experiments on human information-seeking behavior in three different information-seeking environments. The first three experiments utilized a highly-controlled, simulated information-seeking task developed to study human search strategies in citation networks. Emphasis in the fourth and fifth experiments was placed on assessing the value of information for humans in realistic search environments. Subjects search on a topic of their own choice in a data base of fiction in Experiment Four and a data base of technical literature in Experiment Five. After summarizing the experimental results, a conceptual model of how humans value information is presented. The model is then used as a basis for a broad interpretation of the empirical results. Implications of both the empirical and modeling results are considered for the areas of information retrieval logic, system flexibility, retrieval methods, types of aiding, online estimation of information value, and computerizing versus computer-aiding.     

An assessment of instruction provided by library schools in on-line searching

The results of a survey of accredited library schools indicate that instruction provided in on-line searching is widespread and growing but that there is great diversity among library schools in terms of the goals and objectives of the instruction provided. The University of South Florida's new course, Atomated Information Sources and Services, is described.     

TOXLINE: evolution of an online interactive bibliographic database.

The National Library of Medicine has offered TOXLINE, an online interactive bibliographic database of biomedical (toxicology) information since 1972. Files from 11 secondary sources comprise the TOXLINE database. The sources supplied bibliographic records in different formats and data structures. Data from each supplier's format had to be converted into a format suitable for TOXLINE. Three different, successive retrieval systems were used for the TOXLINE database which required reformatting of the data. Algorithms for generating terms for inverted file search methods were tested. Special characters peculiar to the scientific literature were evaluated during search term generation. Developing search term algorithms for chemical names in the scientific literature required techniques different from those used for nonscientific literature. Problems with replication of bibliographic records from multiple secondary sources are described. Some observations about online interactive databases since TOXLINE was first offered are noted.     

Searching the MEDLARS citation file on-line using elhill and stairs: An updated comparison

The purpose of this paper is to update the comparison of the ELHILL (currently ELHILL 3, formerly ELHILL 2) and STAIRS programs as they affect on-line searching of the MEDLARS citation file. The major areas follow the format of the previous paper (data base characteristics, commands, basic terminal interactions, search statements, and printing citations resulting from on-line or off-line processing).     

Frequency and impact of spelling errors in bibliographic data bases

Using a composite sample of over 3600 index terms drawn from 11 different machine-readable bibliographic data bases, estimates were made of the spelling error frequencies of each of these data bases, as well as the frequency of posting to misspelled terms. The terms studied included assigned index terms as well as some terms from titles and abstracts. The frequency of index term misspellings ranged from a high of almost 23% for one data base to a low of less than $\text{1}\text{2}\text{\%}$ for another data base. The frequency of posting to misspelled terms ranged from about one posting in 8000 citations for one data base, to about one posting in 160 citations in another data base. The impact of these error rates is discussed for the tape supplier, tape user and end user. Some suggestions are given regarding search strategry.     

How are we searching the World Wide Web? A comparison of nine search engine transaction logs

The Web and especially major Web search engines are essential tools in the quest to locate online information for many people. This paper reports results from research that examines characteristics and changes in Web searching from nine studies of five Web search engines based in the US and Europe. We compare interactions occurring between users and Web search engines from the perspectives of session length, query length, query complexity, and content viewed among the Web search engines. The results of our research shows (1) users are viewing fewer result pages, (2) searchers on US-based Web search engines use more query operators than searchers on European-based search engines, (3) there are statistically significant differences in the use of Boolean operators and result pages viewed, and (4) one cannot necessary apply results from studies of one particular Web search engine to another Web search engine. The wide spread use of Web search engines, employment of simple queries, and decreased viewing of result pages may have resulted from algorithmic enhancements by Web search engine companies. We discuss the implications of the findings for the development of Web search engines and design of online content.     

A Zipfian model of an automatic bibliographic system: an application to MEDLINE.

A Zipfian model of an automatic bibliographic system is developed using parameters describing the contents of it database and its inverted file. The underlying structure of the Zipf distribution is derived, with particular emphasis on its application to work frequencies, especially with regard to the inverted flies of an automatic bibliographic system. Andrew Booth developed a form of Zipf's law which estimates the number of words of a particular frequency for a given author and text. His formulation has been adopted as the basis of a model of term dispersion in an inverted file system. The model is also distinctive in its consideration of the proliferation of spelling errors in free text, and the inclusion of all searchable elements from the system's inverted file. This model is applied to the National Library of Medicine's MEDLINE. The model carries implications for the determination of database storage requirements, search response time, and search exhaustiveness.     

An analysis of Web searching by European AlltheWeb.com users

The Web has become a worldwide source of information and a mainstream business tool. It is changing the way people conduct the daily business of their lives. As these changes are occurring, we need to understand what Web searching trends are emerging within the various global regions. What are the regional differences and trends in Web searching, if any? What is the effectiveness of Web search engines as providers of information? As part of a body of research studying these questions, we have analyzed two data sets collected from queries by mainly European users submitted to AlltheWeb.com on 6 February 2001 and 28 May 2002. AlltheWeb.com is a major and highly rated European search engine. Each data set contains approximately a million queries submitted by over 200,000 users and spans a 24-h period. This longitudinal benchmark study shows that European Web searching is evolving in certain directions. There was some decline in query length, with extremely simple queries. European search topics are broadening, with a notable percentage decline in sexual and pornographic searching. The majority of Web searchers view fewer than five Web documents, spending only seconds on a Web document. Approximately 50% of the Web documents viewed by these European users were topically relevant. We discuss the implications for Web information systems and information content providers.     

A cost comparison of manual and automated circulation systems in university libraries: The case of the Ibadan University library

This paper presents the results of a comparative cost study of the manual circulation system and experimental automated system in a university library in Nigeria. Two sets of data were collected: one on the existing manual circulation system and the other on the experimental automated system on an Apple II microcomputer. Eight different circulation activities were identified for evaluation for which the direct labor cost of circulating a book on each system was calculated. The experimental automated system was found to be less labor intensive than the manual system, although overall unit cost of book circulation on the automated system was higher than on the manual system ($0.59 and $0.49, respectively). Factors attributed to the higher unit cost on the automated system were the cost of equipment and the low circulation figure. However, the automated system was found to be more effective in providing up-to-date and accurate data required for the monitoring of the library stock.     

Using an online microfiche catalog for technical service and retrieval of bibliographic data

A prototype system is created that integrates a microfiche catalog into an online computer system for bibliographic control. Costs and operational data are collected and analyzed. The system permits the more economical microfiche storage of catalog records than would be feasible for comparable online magnetic disk storage. Experimental tests demonstrate the feasibility of the online microfiche catalog system for use in library technical services and retrieval of bibliographic data. The primary result of the project is the creation of a completely operational facility, including all equipment, software, procedures, and data bases necessary to demonstrate the system. A second set of results is derived from the experimental use of the system and the evaluation of costs and times for various operations. The cost effectiveness of the online microfiche catalog is demonstrated.     

手动变速器轴承箱的分析与强化

针对轴承箱倒档惰轮轴安装处倒档出现开裂问题,对轴承箱结构及受力进行了分析,同时对壳体相关部分做了强化。CAE分析结果表明,壳体改进后的应力明显减小,达到了设计的要求,后续的倒档破坏性试验中没有发生壳体开裂的现象。同时,对惰轮的受力分析表明,改变惰轮安装位置,可以有效减小倒档轴对壳体的作用力。总结故障的根本原因是由于惰轮的承载能力不足造成的,采用更换惰轮的材料的措施,提高了齿轮承载能力,避免类似故障再次发生。     

Effects of emotion control and task on Web searching behavior

The study investigated how users’ emotion control and search tasks interact and influence the Web search behavior and performance among experienced Web users. Sixty-seven undergraduate students with substantial Web experience participated in the study. Effects of emotion control and tasks were found significant on the search behavior but not on the search performance. The interaction effect between emotion control and tasks on the search behavior was also significant: effects of users’ emotion control on the search behavior varied depending on search tasks. Profile analyses of search behaviors identified and contrasted the most commonly occurring profiles of search activities in different search tasks. Suggestions were made to improve information literacy programs, and implications for future research were discussed.     

A common interface for accessing document retrieval systems and DBMS for retrieval of bibliographic data

Due to their ready availability, database management systems are being applied to bibliographic databases with increasing frequency. This is being done in spite of the fact that although DBMS query languages tend to be very powerful, they are far too complex for the casual user. It is proposed that PSI, an existing virtual-system intermediary for document retrieval systems, be extended to include access to DBMS containing bibliographic data in order to circumvent the complexity problem or the casual user. PSI currently provides a common command language for access to multiple document retrieval systems. It is shown that PSI could be extended to provide this same command language to access DBMS, whether the DBMS are relational or network.     

Monitoring and evaluation of on-line information system usage

The paper presents a background survey of the existing state-of-the-art as it relates to monitoring of information systems. It addresses both historical and current approaches and both manual and automated techniques. The general concept of automated monitoring into a well-defined methodology, categorizing the generic uses for monitoring, identifying specific objectives of monitoring and translating these objectives into detailed parameters are developed. Methodologies, techniques and theoretical foundations essential for analyzing monitored data are formulated. Desirable computer-based support requirements for data analysis also are discussed. Conclusions and implications for future research and development efforts in monitoring and evaluation of on-line information systems are highlighted.     

A comparative study of multiple attribute tree and inverted file structures for large bibliographic files

A variety of data structures such as inverted file, multi-lists, quad tree, k-d tree, range tree, polygon tree, quintary tree, multidimensional tries, segment tree, doubly chained tree, the grid file, d-fold tree. super B-tree, Multiple Attribute Tree (MAT), etc. have been studied for multidimensional searching and related problems. Physical data base organization, which is an important application of multidimensional searching, is traditionally and mostly handled by employing inverted file. This study proposes MAT data structure for bibliographic file systems, by illustrating the superiority of MAT data structure over inverted file. Both the methods are compared in terms of preprocessing, storage and query costs. Worst-case complexity analysis of both the methods, for a partial match query, is carried out in two cases: (a) when directory resides in main memory, (b) when directory resides in secondary memory. In both cases, MAT data structure is shown to be more efficient than the inverted file method. Arguments are given to illustrate the superiority of MAT data structure in an average case also. An efficient adaptation of MAT data structure, that exploits the special features of MAT structure and bibliographic files, is proposed for bibliographic file systems. In this adaptation, suitable techniques for fixing and ranking of the attributes for MAT data structure are proposed. Conclusions and proposals for future research are presented.