Since 1977, the International Online Information Meeting (IOLIM) in London has been the most important conference for users and producers of electronic information. The organiser of the conference is Learned Information Europe Ltd, a UK-based commercial organisation. In order to measure the impact of these conferences on the library and information science literature in general, a concept of conference impact factor (CIF) is explored for the first time. Following the pattern of journal impact factor (JIF), the study presents a methodology for exploring the characteristics of a core international conference and measuring its impact. The study used the online citations databases in DIALOG, as well as the CD-ROM version of
Library and Information Science Abstracts
. Through statistical and bibliometric analysis, the paper provides quantitative information about geographic distribution of members of Organising Committees, Referee Panels, authors, delegates and citations. Knowledge export of the conference is measured by the subject categories of citing journals. A list of the top most cited papers of the
Proceedings
is presented, as well as the names of the citing authors and titles of the journals. Via time series, the study highlights trends and developments reflected by IOLIM.