This study, conducted at the University of Wyoming (UW), illustrates the complexity involved in making reasonable decisions about which electronic products to make available in the library. UW is a member of the CARL Alliance, and utilizes the CARL integrated online system which includes an OPAC, circulation, serials control, bibliographic maintenance and acquisitions modules. When the CARL Alliance acquired and loaded ERIC in April of 1992, UW Libraries added it to the OPAC menu. Striking differences were noticed in the amount of information retrieved by the two systems. The concept of descriptors is key to understanding how the ERIC database is structured. Both keyword and controlled vocabulary searches are accommodated by Dialog (CD-ROM). For the CARL interface, a Word search retrieves words from all fields of a record; while Subject Word and Subject Browse searches retrieve major descriptors only. This study was undertaken with the idea that some kind of systematic and orderly collection of data was needed in order that librarians might make an informed comparison of the capabilities of the two systems. User education relating to ERIC on CARL is called for on the part of libraries finding themselves with no other access to the database; the incomplete sets of retrieved information are cause for concern. Users need to be aware of the shortcomings of CARL, and institutions with large numbers of off-campus students have a particular responsibility to inform their clients of potential problems with their searches. Librarians should evaluate their own working environments to determine if impediments to access such as those found at University of Wyoming exist in their local situations. (Contains 21 references.) (AEF)