factor indicates that it contains top quality articles, but because Rejoiner-The Multiple Meanings of Impact it publishes a relatively small number of articles, its influence Factors on scholarly communication is less than a journal with a similar impact factor, but that publishes more articles, such as JASIS.
Sir:
To address two other issues raised by Mr. Garfield, we do not believe there is a need to divide what we term ''journal In response to Mr. Garfield's recent letter (in Vol. 49, No. impact factor'' by 100 or 1,000 to produce more manageable 8, p. 768), we believe our communication concerning the term numbers, because the 100,000-citations figure quoted by Mr. ''impact factor'' deals not only with ''semantic'' questions, but Garfield would apply to only a tiny fraction of the journals in also more fundamental issues concerning what impact factor the ISI database. We concede that we did not consider the really measures that have conceptual implications for its use by possibility that ''article impact factor'' (our proposed new name scholars.
for ISI's ''impact factor'') could be confused with the citation We do not view the number of citations received in 1994 to frequency of a specific article. articles published in 1992 and 1993-a measure that we pro-Mr. Garfield quite correctly points out that many different posed terming ''journal impact factor''-as simply a matter of citation measures are possible. In fact, Vinkler (1988) has idenjournal productivity (although it undoubtedly correlates with tified 39 different bibliometric measures. The challenge for indithe number of articles produced), but rather as a measure of a viduals using or studying citation data is to determine what the journal's actual impact on the scholarly communication process.
various citation measures are, in reality, measuring and to not ISI's impact factor, devised in order to control for journal size, claim more for a given measure than it can deliver. serves as a quality measure. However, as discussed in our communication, a journal publishing a small number of highly cited articles is not necessarily having much impact on the scholarly
Stephen P. Harter communication process. In contrast, a journal with a lower im-Thomas E. Nisonger pact factor that produces a greater number of articles-and thus School of Library and Information Science receives more citations-is exerting a larger impact on the Indiana University scholarly communication process. It is possible that impact on Bloomington, IN 47408 scholarly communication is more closely related to article pro-E-mail: