Managers and students of management in India predicted performance in human/computer system from information about the user's proficiency with computers and the power of the system. User proficiency was defined as the user's ability to work with computers; and system power was defined as the computer's ability to store, retrieve, and analyze data. Five different models were proposed for how used proficiency and system power are expected to determine performance. These were (a) a matching model in which optimal performance is achieved when the power of the system is judged to be compatible with the proficiency of the user, (b) an averaging model in which expected performance is the average of the values of user proficiency and system power, (c) a multiplying model in which performance is the product of the values of user proficiency and system power, (d) a human/computer ratio model in which performance is determined by the ratio of system power over total effort, and (e) a computer/human ratio model in which performance is determined by the ratio of user proficiency over total effort. Participants rated 16 combinations of user proficiency and system power from a 4 x 4 factorial design. The pattern of ratings indicated that 51 percent used a multiplying model and 25 percent used an averaging model; whereas, only 6 percent used the matching model and 4 percent used a ratio model. The remaining 14 percent did not follow any model clearly. Implications of these results were discussed for the design of the human/computer interface, training and selection of users, and the cost-benefit trade-offs for investment in user training versus equipment acquisition.