The past 50 years have seen great progress in the measurement of patient-based outcomes for older populations. Most of the measures now used were created under the umbrella of a set of assumptions and procedures known as classical test theory. A recent alternative for health status assessment is item response theory. Item response theory is superior to classical test theory because it can eliminate test dependency and achieve more precise measurement through computerized adaptive testing. Computerized adaptive testing reduces test administration times and allows varied and precise estimates of ability. Several key challenges must be met before computerized adaptive testing becomes a productive reality. I discuss these challenges for the health assessment of older persons in the form of 10 "Ds": things we need to deliberate, debate, decide, and do.