As the prevalence of computer-based technologies increases throughout socie
ty, so does the likelihood that older adults will be required to interact w
ith them. Unfortunately, such systems often appear to older adults to be to
o hard to use and too hard to learn. We provide examples highlighting the o
pportunities available to behavioural science to affect training and system
design through practically relevant research. We focus on our research on
ageing, computer use, and training to support our assertion that applied re
search aimed at designing training materials and system interfaces to enhan
ce the performance of older adults can and should be driven by psychologica
l theory. The data presented and studies reviewed here clearly demonstrate
that theory is critical for predicting age differences in computer use, for
guiding the development of both training and design interventions for olde
r computer users, and for reconciling conflicting findings in the design-ev
aluation literature.