Computer-Adaptive Functioning Testing

Computer-adaptive functioning testing applies the logic of computerized adaptive testing to the measurement of functioning and disability outcomes, such as physical function, mobility, and daily activity. Instead of administering a fixed list of items to everyone, it draws on a precalibrated item response theory item bank and an algorithm that tailors the test to each respondent in real time. After each answer, the algorithm updates its estimate of the person's underlying function level and selects the next item that will be most informative at that estimate, continuing until a target precision is reached or a maximum number of items is administered. The approach was central to the United States PROMIS initiative, whose physical-function item bank Rose and colleagues evaluated in 2008 and whose first wave of adaptive instruments Cella and colleagues described in 2010. The result, framed here specifically for disability and rehabilitation outcomes, is measurement that achieves high precision with far fewer items than a fixed questionnaire, reducing respondent burden for people who may already face fatigue or communication barriers.