User interface (UI) agentsare new intelligent user interface technologies that can help pwent people fmm making mistakes by guiding them through information system tasks. To be effective, UI agents must be applied to tasks that exploit the potentials of UI agentswithout expecting them to perform beyond their constraints. The potentials and constraints of two kinds of UI agents (wizards and guides) were consideti and criteria for the application of these UI agents were outlined. An empirical study of 61 0S/2 Warp beta testem with varying degrees of computer experience is~ ported that assessed respondents’ penxptions of the importance, tlequency, and difficulty of 57 information system tasks. Empirical and rational analyses were used to select a set of tasks to which Ul agent technologies were applied in the latest release of IBMs 0S/2 Warp operating system.