摘要:

AbstractA new testing process is described designed to compare conventional retrieval (MEDLARS) and automatic text analysis methods (SMART). The results obtained with a collection of documents chosen independently of either SMART or MEDLARS indicate that a simple automatic extraction of keywords from document abstracts produces a 30 to 40 percent loss compared with MEDLARS indexing. A replacement of the unranked Boolean searches used in MEDLARS by the standard ranked output normally provided by SMART reduces the loss to between 15 and 20 percent. When an automatically generated word control list or a thesaurus is used as part of the SMART analysis, the results are comparable in effectiveness to those obtained by the intellectual MEDLARS indexing. Finally, the incorporation of user feedback procedures into SMART furnishes an improvement over the normal MEDLARS output of 15 to 30 percent.One concludes again that no technical justification exists for maintaining controlled, manual indexing in operational retrieval environments.

ISSN:0002-8231    

DOI:10.1002/asi.4630230202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1972

数据来源: WILEY

摘要:

AbstractA selected sample of U.K. University, industrial and Government scientists were given a current‐awareness service for 18 months, in order to investigate the practicability and problems of such a service. Six hundred profiles were run, using the natural‐language data basesChemical Titles and Chemical‐Biological Activitiesproduced by Chemical Abstracts Service.Precision and recall were measured, and correlations between profile performance and such factors as subject area and profile logic were investigated statistically. Precision and recall failures were analysed and various improvements to the system were suggested as a consequence.It was concluded that a viable computerised current‐awareness service based on searching natural language could be

ISSN:0002-8231    

DOI:10.1002/asi.4630230203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1972

数据来源: WILEY

摘要:

AbstractIn order to help cataloging instructors evaluate texts for beginning cataloging courses, analyses of the contents and citations are used to point out the different approaches and features used by 4 authors. An attempt is made to correlate the percentage of citations in each area of cataloging with the percentage of pages devoted to that same aspect. Three of the 4 texts were published from 1967 to 1969 and a comparison of the citations reveals that the 3 texts only have 5 citations in common. An age analysis of the citations shows that in 3 texts the age of the citations are similar, while the fourth text cites materials considerably older. The citations used by the 3 recent texts are divided into 10 topics and the 3 authors' citations are listed together according to the topic in order to show the differences in the sources used by the authors.

ISSN:0002-8231    

DOI:10.1002/asi.4630230204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1972

数据来源: WILEY

摘要:

AbstractThis paper presents an experimental study of index‐term frequency as a factor in retrieval performance. The frequency of an index term, or its “breadth” as it is called here, is the number of postings made to the term in a given collection. The question is asked: Of index terms assigned to documents, which function most effectively in retrieval, the most used or popular terms, or those which are used relatively infrequently? The experiment is a retrieval experiment and uses the Cran‐field‐Salton data. Breadth of indexing is varied by nonrandomly deleting terms from documents. Retrieval output is evaluated using the Expected Search Length measure of retrieval effectiveness as well as the usual precision and recall. The Wilcoxen Test is used to determine the statistical significance of the different indexings. The results show that the “optimal” breadth of indexing is a variable, depending on user needs: if a few documents are wanted or high precision is desired, then narrow terms are more effective than broad ones; if, on the other hand, all or most relevant documents are wanted, then broad terms are better. An argument, however, can be made for the quality of narrow terms, since when these terms are deleted precision never improves, whereas deleting broad terms always results in higher precision. A corollary experiment is carried out to compare two indexings of the same average breadth where one indexing consists of semantically appropriate terms—terms taken from the document title—and the other consists of merely “reasonable” index terms. The results suggest that title‐term indexing

ISSN:0002-8231    

DOI:10.1002/asi.4630230205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1972

数据来源: WILEY

摘要:

AbstractA semantic differential (SD) is a commonly used instrument which can be used to reliably measure attitudes toward a variety of objects or concepts. Each SD consists of a series of bipolar adjective scales on which a respondent reacts, in relation to the object or concept of interest. To interpret completed SDs, it simplifies the procedures and aids in the development of theory if the adjective scales are grouped into one or more independent clusters. The primary purpose of this study was to identify those clusters (or dimensions) applied by a user of an on‐line user‐oriented reference retrieval system when he reacts toward such a system.Seventy‐one who used or were familiar with a working on‐line reference retrieval system completed a packet of 20 SDs, each consisting of the same 19 adjective scales. The correlations among the scales were factor analyzed. Three independent dimensions were identified. Factor I was labeled “evaluative‐specific” and accounted for over 23% of the total variance. Factor II was called “desirability”; it accounted for over 17% of the total variance. And, Factor III, entitled “enormity” accounted for over 10% of the total variance. Another analysis showed the factor structure to be highly reliable. Therefore, if the derived three dimensional structure underlies users' attitudes toward a more general class of retrieval systems, then undimensional or unstructured system evaluations of users' attitudes will be simplistic and possibly misleading.In order to construct a working semantic differential, 10 adjective scales were identified which best represented the three dimensions. Brief instructions are included which outline how to use this SD. The discussion is mainly concerned with the obtained factor structure and the need for a predictive rep

ISSN:0002-8231    

DOI:10.1002/asi.4630230206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1972

数据来源: WILEY

摘要:

AbstractSince 1966 the federal government has made millions of dollars available for the purchase of instructional materials for use in the nation's elementary and secondary schools. While the federal funds have benefited students and teachers through the establishment of materials collections, relatively little research has been conducted in the use of these materials.The experimental test described in this article shows that productivity in regard to the subject literature supporting the school library media center concept increases or decreases in correspondence with the amount of federal funds made available for each fiscal year. This subject literature represents the state of knowledge (source) in a communication process to the learner (destination). It is suggested that if federal funds were made available for the systematic study of the phenomena of use of learning materials, new knowledge and a more effective communication system would result. Thus, the teacher's knowledge and understanding of the use of instructional materials, which will ultimately determine the use or nonuse of such materials, would increase, and children would benefit.

ISSN:0002-8231    

DOI:10.1002/asi.4630230207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1972

数据来源: WILEY

ISSN:0002-8231    

DOI:10.1002/asi.4630230208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1972

数据来源: WILEY

ISSN:0002-8231    

DOI:10.1002/asi.4630230209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1972

数据来源: WILEY

ISSN:0002-8231    

DOI:10.1002/asi.4630230210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1972

数据来源: WILEY

ISSN:0002-8231    

DOI:10.1002/asi.4630230211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1972

数据来源: WILEY