We thank Mr. Randall for reviewing the SCIENCE CITATION INDEX 1964 and bringing it to the attention of the readers of SCI-TECH NEWS. Some of the points made in the description call, perhaps, for elaboration, lest there remain a misunderstanding. For instance, Randall’s review states that there is "extensive coverage of the life-science journals but chemistry is well represented and there are mathematics and physics journals included in the list." The latter part of this statement is misleading. In fact, the 1964 SCI which Randall examined had a very good coverage of physics even though it "only" processes about 50 physics journals in addition to the mathematical and interdisciplinary publications. In source coverage alone it thereby indexes more than half of all the specific articles abstracted by PHYSICS ABSTRACTS. In the 1964 SCI, as part of a long-range plan for journal expansion, the coverage of physics, mathematics, and allied fields was improved over that in the 1961 SCI, and has been increased even more extensively for the 1965 SCI.

The prime reason why "coverage" is often underestimated in discussions of various types of indexing services is a failure to take into account the fundamental law of bibliographic scattering enunciated by Bradford (1, 2) and elaborated by Cole (3). This point is illustrated dramatically in the field of synthetic chemistry where a recent study disclosed that "only" 52 journals produce 92% of the total pertinent literature (4).

One must also consider the rather obvious but important fact that the world's scientific literature is more heavily bio-medical than physical. In illustration, the INDEX MEDICUS covered about 140,000 papers in 1961 while PHYSICS Abstracts covered 20,000. This ratio must be reflected in an index such as the SCIENCE CITATION INDEX if it is to provide a fair representative coverage of all major branches of science.

In trying to judge the SCI's accuracy, Randall described the results of his check of 20 references (out of more than two million estimated for the 1964 SCI) using a non-random sample from two neighboring articles in one journal issue. By stating that there were two errors in this trivial sample, he unfortunately implies a 10% error factor in the SCI. One of these errors was the inclusion of "V" as one of the initials in a name presented in the journal as "Vgl. CK. Briggs." In the second error, "Sutton" was improperly key-punched as "Stutton" where the entry is found. Randall amusingly illustrates human fallibility all too well by stating that the reference to Briggs appears on p.195 when in fact it is on p.194. Might we conclude that all the work of the reviewer has an error rate of 50%?

The reviewer seems to appreciate the utility of the SCI since he notes that "the potentials of this unorthodox approach to information are so intriguing that we hope the service will be continued long enough to enable us to make a careful investigation of its efficacy..." We wonder why, however, Randall has SCI-Tech librarians "selfishly" wishing that the coverage were directed to the engineering and physical science journals rather than to the life sciences -- and then fails to mention that SCI covers the one greatest source of technological information available -- all U.S. patents. As just a part of the coverage in engineering, the SCI processes all the IEEE publications and has good coverage of instrumentation journals. SCI-TECH, of course, includes pharmaceutical, aero-space, chemical and other firms that have a considerable interest in bio-medicine as well as engineering and physics. We believe the service Randall is hoping for already exists in the ever-expanding SCIENCE CITATION INDEX, and the surest way to guarantee the continuance of a new service is to support it in its formative years. Thanks to the response to the SCI during its first year, the SCI's coverage in 1965 will, in addition to all 1965 U.S. patents, exceed 1,000 journals and will fully represent the various branches of science and technology.
 
 

Eugene Garfield, Ph.D.
Director
Institute for Scientific Information
Philadelphia, PA 19106