We define and describe the new field of gerontechnology, assess the challenges facing academics and practitioners in designing technology products for older users, and provide some practical advice. We review expected age-related changes in perception, cognition, and psychomotor performance and suggest principles for accommodating such changes with better design. We introduce parameters for using goals, operators, methods, selection rules (GOMS) modeling techniques to improve the design process and provide an example of such modeling for a mobile phone task.