Information system (IS) support of human problem solving during the complex task of auditing within a computer environment was investigated. 74 computer audit specialist professionals from nine firms participated in the field experiment. Task accomplishment behavior was recorded via a computerized activity-logging technique. Theoretical constructs of interest included: 1) IS problem-solving support, 2) task domain knowledge, and 3) decision-making behavior. It was theorized that task domain knowledge influences the type of IS most functionally appropriate for usage by that individual. IS task presentation served as the treatment variable. Task domain knowledge was investigated as a moderating factor of task accomplishment Task accomplishment, the dependent variable, was defined as search control strategy and quality of task performance. A subject's task domain knowledge was assessed over seven theoretical domains. Subjects were assigned to higher or lower task domain knowledge groups based on performance on professional competency examination questions. Research hypothesis one investigated the effects of task domain knowledge on task accomplishment behavior. Several task domain knowledge bases were found to influence both search control strategy and task performance. Task presentation ordering effects, hypothesis two, were not found to significantly influence search control strategy or task performance. The third hypothesis investigated interaction effects …