The purpose of this research was to compare two widely used computer-assisted career guidance (CACG) systems, DISCOVER and System of Interactive Guidance and Information (SIGI). The goals were to: (1) assist practitioners in learning more about the benefits of using a CACG system as a component of total program services; (2) assist CACG system developers in revising software and support materials to more fully meet the needs of practitioners and users; and (3) assist researchers in planning further investigations concerning the optimal use of this technology. The first study examined the effects of DISCOVER and SIGI on occupational certainty, vocational identity, career exploration, and decision making style of 109 college students. Students were randomly assigned to either DISCOVER, SIGI, or a control condition that involved unstructured use of materials in a university career center. Analyses failed to reveal significant differences among groups on the dependent measures. The second study used the same population to examine the social influence of DISCOVER and SIGI. User perceptions of expertness, attractiveness, and trustworthiness were compared between users of DISCOVER, SIGI, and a control group of nonusers. Findings showed that DISCOVER and SIGI users had more positive perceptions of the attractiveness of systems than nonusers, indicating one effect of system use. It was also found that users attributed high levels of expertness, attractiveness, and trustworthiness to the computer systems, sometimes exceeding levels attributed to effective counselors. The evaluation instruments and 40 references are attached. (LLL)