Older adults' use of design features in task environments may be influenced by age-related declines in cognitive, sensory, and movement abilities. Current usability analysis techniques do not provide a clear method for measuring the effectiveness of specific computer features designed to support usage for adults of all ages. In this review we discuss different approaches for assessing and understanding age-related differences in performance on common computer tasks. We describe research in our laboratory that systematically assessed how text entry performance was influenced by the design features of a virtual keyboard. Three analysis techniques were used to identify display features that facilitate effective performance by younger and older adults. First, component analysis allowed us to independently examine design features previously shown to affect individual task components, namely movement and visual search. Second, usage analysis permitted assessment of the text entry task in the target context. Third, transfer analysis allowed examination of specific design features that might facilitate more natural and effective performance following different levels of practice. Through these techniques, we identified several keyboard features that contribute to optimal performance for older adults without hindering younger adults. Use of these features may be generalized to designs for other input devices and tasks. Incorporating our techniques into usability analysis can contribute to development of systems that are easier to use for a broader population.