Do Impact Factors change with a change of medium? A comparison of Impact Factors when publication is by paper and through parallel publishing.

This paper reports the results of a bibliometric analysis of scholarly journals in the field of psychology. The Impact Factors of a sample of journals have been collected from Journal Citation Reports (JCR) provided by ISI. Changes in the Impact Factors were monitored annually over two periods, 1994-1995 and 2000-2001, the years before and after electronic journals appeared. The collected Impact Factors of scholarly journals from these two periods are compared in the available media. As a result, it is found that Impact Factors of 2000 and 2001 were significantly higher than those of 1994 and 1995 in the journals published by parallel publishing (combination journals - simultaneous publication of paper and electronic journals). In particular, the Impact Factors of the combination journals increased after the journals transformed their available media from paper journals to combination ones. By contrast, in the case of paper journals, there was no significant difference between the Impact Factors of 1994 and 1995 and those of 2000 and 2001. Additionally, it is possible to infer from later analyses that the citation rate is not changed by the available media in the authoritative journals which have comparatively high Impact Factors. In journals with low Impact Factors, on the other hand, the available media influences the citation rate. [ABSTRACT FROM AUTHOR]