SECTION 18 



CITATION INDEXING 



18.1. Dissemination and Retrieval of Genetics In- 

 formation Through Interdisciplinary Citation 

 Indexing. Eugene Garfield and Irving H. 

 Sher (Philadelphia, U.S.A.). 



The difficulties in handling the highly inter- 

 disciplinary genetics literature by conventional 

 methods led to a study of citation indexing, a 

 method used in legal literature. Citation indexing 

 overcomes the terminological barriers of lan- 

 guage-oriented systems and does not require 

 scarce scientifically trained indexers. It uniquely 

 discloses the bibliographic descendants of ear- 

 lier papers rather than their antecedants — as in 

 conventional systems. A citation index iden- 

 tifies the subsequent papers citing earlier target 

 papers. 



For three years methodologies for compiling 

 citation indexes by computer have been studied. 

 Several experimental indexes were compiled 

 and compared to other systems. Over 2,000,000 

 citations from the published literature have 

 been processed! Invaluable bibliographical, 

 sociological, and historical statistical data have 

 been obtained as by-products and various 

 author, journal, and chronological utilization 

 factors determined. 



Citation indexing is based upon a posteriori 

 indexing by citing authors, making the litera- 

 ture a dynamic tool for creative research. New 

 or previously unknown correlations and in- 

 sights are obtained since the citation index 

 integrates the "old" literature with the new, 

 often in dramatic ways. The enormous prolif- 

 eration of the literature, anathema and disabling 

 in conventional a priori systems is highly 

 beneficial in citation indexing. Its self-organizing 

 properties automatically increase specificity as 

 the literature grows. As citation input is 

 increased one approaches critical mass — the 

 coverage necessary to insure a known degree 

 of reliability for a negative search result, an 

 important indicator that new research is needed 

 or justified. 



18.2. (D) The Genetics Citation Index. Irving H. 

 Sher and Eugene Garfield (Philadelphia, 

 U.S.A.). 



A citation index is a directory of cited litera- 

 ture references, each of which is accompanied 

 by a list of citing source documents. Typically, 

 the user specifies a target paper in which he is 

 interested. In the citation index he locates the 

 author and specific article first. From there, the 

 index displays the more recent papers that have 

 cited the target paper, thus bringing him for- 

 ward in time through subsequent interdis- 

 ciplinary developments. We have prepared sev- 

 eral types of genetics citation indexes for com- 

 parative evaluation including: 



1. Comprehensive interdisciplinary citation 

 indexes compiled from 2,000,000 references. 



2. A Genetics Citation Index selectively ex- 

 tracted from a file of 1.4 million references 

 appearing in 550 life science journals 

 published in 1961. 



3. Genetics Citation Indexes derived from 

 long runs of "hard core" genetics journals. 



Microfilms of the indexes will be displayed and 

 a sample search of the files will illustrate the 

 unique speed and power of this new tool for 

 information retrieval. 



In contrast to conventional systems, valuable 

 information is obtained from a Citation Index, 

 even when no citations are disclosed, since this 

 implies that the target paper has not been ex- 

 tended. A demonstration of "cycling" will 

 show how a search can be expanded by selecting 

 new targets from the bibliographies of papers 

 which cite the target paper, continuing the 

 process until an optimum list of papers has 

 been retrieved. After the pedagogical demonstra- 

 tion, spontaneous literature searches will be con- 

 ducted for each visiting geneticist and copies of 

 the search bibliography provided. 



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