Being able to conveniently measure physical function is important to physical educators, athletic trainers, therapists, and on larger scale community health surveyors. Various tests exist for the assessment of physical function, but they are often delivered either in a lengthy information rich format (e.g., a 30-question instrument will be too long to field testing) or in a simplistic lack of information format (e.g., a 3-question instrument may not be able to cover various conditions in practice). Function assessment could be delivered via a computer adaptive test (CAT), with the use of a stationary desk-top computer, and software designed to pick questions based on the examinees prior response. The prime advantage of CAT is that it potentially delivers a brief, information rich, and succinct assessment. As a result, total items used in a test may be the same or less than those used in conventional testing, but the information collected will be richer. Since the desktop computer is a stationary device it is not always feasible for use in the field or clinical setting. The best probable solution for field or clinical function assessment would be stand alone CAT function assessment via a personnel digital assistant (PDA). PDA are handheld computers, which can perform many of the vital functions of a computer yet because of their small size they are mobile and provide a convenient platform for field or clinical CAT assessment application. This condensed yet information rich, PDA-based CAT assessment can be used by physical educators assessing gross motor function or by therapist assessing physical function and can potentially provided timely, large scale convenient assessment of individuals. Using knee assessment as an example, the conventional practices and its limitations will be reviewed, procedure and steps to construct a PDA-based CAT assessment will be described in detail, and potentials, challenges and research needs of the new assessment will be addressed.Keyword(s): assessment, exercise/fitness/physical activity, measurement/evaluation