VISIBLE COLLEGES - THE SPECIAL INTEREST GROUP CO-MEMBERSHIP STRUCTUREOF ASIS

ASIS currently (1992) charters twenty Special Interest Groups (SIGs) T he SIGS are intended to ''give members with similar professional speci alties the opportunity to exchange ideas and keep themselves informed about current and discrete [sic] developments in their fields. The act ivities ... provide clear indication of the diverse interests and need s of ASIS members.'' [1, P. 17]. Membership in one SIG is included in the basic dues; additional SIGs can be added for increased dues paymen ts. Patterns of association among SIGs, based on choices made by those members selecting two or more SIGs (at some cost to the individual), were studied and the underlying ''intellectual structure'' of ASIS ill uminated using the multivariate techniques commonly associated with au thor cocitaiton analysis. Nine hundred forty-one of the approximately 3800 members included in the 1992 ASIS Directory are listed as members of 2 or more SIGs. A mapping and clustering of SIG co-membership data based on these 941 members (measured as the ''joint conditional proba bility'''of membership overlap) produced a two-dimensional map with th e central area occupied by two clusters jointly representing the centr al focus of ASIS member interests-information systems implemented in o rganizations-with peripheral placement of those SIGs linking to the ou t-of-ASIS disciplinary communities of researchers and users. The dimen sions themselves demonstrate the two major organizing principles -- a broad subject orientation (''hard'' to ''soft'' disciplinary SIGs) and a grounding in more ''formal'' theoretical research (SIG/ALP, SIG/CR) versus human concerns (SIG/MED, SIG/BSS).