16.2.3 ISI cited by versus ISI general search

As indicated above, the ISI Cited By search function includes citations to non-ISI listed journals, books, book chapters and conference papers in addition to citations to ISI-listed journals (as in the ISI General search function). The difference between the ISI Cited By search and the ISI General search varies enormously between the various disciplines.

As is apparent from Figure 5, for four of our five academics working in the Sciences, there is virtually no difference between their citation records in the two different types of ISI searches. Their citation records increase only marginally by 0.5% to 4.0%. The simple reason is that in these four disciplines most journals are ISI listed and most academics only publish in journals. In fact, in these four cases the only additional citations in the ISI Cited By search function were caused by “stray citations”, i.e. citations to ISI-listed journals that included either minor misspellings or referred to articles in press, and hence were not correctly merged into the master record by ISI data entry staff.

Figure 5: Citations for ISI General and ISI Cited By Search: Science disciplines

The fifth academic, who works in Computer Science, shows a fairly typical citation pattern for Engineering & Computer Science. He has a non-negligible number of additional citations in the ISI Cited By search function, increasing his overall ISI citation record by 31%. In fact, this still seriously underestimates his citation record in ISI-listed journals as it does not include the 700-odd ISI citations to a book for which he is the second author. As indicated above, ISI ignores citations to the second and further author for non-ISI publications. If these were included the Computer Science academic would see his publication record double between the two different types of ISI searches.

Figure 6: Citations for ISI General and ISI Cited By Search: Social Science and Humanities disciplines

In contrast, as is shown in Figure 6, our five academics working in the Social Sciences and Humanities show very large differences between their citation records in the two types of ISI searches. This difference ranges from having nearly 2.5 times as many citations in the IS Cited By search function for the Business and Political Science academic, around 4.5 times as many citations for the Linguist, and 5.5- 6 times as many citations in the ISI Cited By search function for the Education and the Cinemas Studies academic.

Consequently, the differences in citation records between the Sciences on the one hand and the Social Sciences and Humanities on the other hand are much larger in the ISI General search function than in the ISI Cited By search function. In the former case, academics in the Sciences on average have 17 times as many citations as the academics in the Social Sciences and Humanities, whilst in the latter case this is reduced to 5 times as many citations.