Understanding the functional impact of asthma on health-related quality of life (HRQOL) can be substantially improved using item response theory (IRT) and competing objectives of more practical and more precise assessments can be achieved over a wide range of severity levels using computerized adaptive testing (CAT), which matches questionnaire items to each patient's level. If more available, such information could be useful in enhancing patient-caregiver communication. Among the limiting factors is the impracticality (respondent burden) of today's HRQOL measures. Short-forms (e.g., SF-36", AQLQ) are more practical, however, "ceiling" and "floor" effects limit their ranges and they lack the precision to detect changes in individual patient scores. To address these deficiencies, the aims of Phase I are to use previously developed IRT calibrations for a combined "pool" of items from asthma-specific questionnaires covering major domains of asthma impact to: (1) administer asthma impact, asthma control, and generic HRQOL measures as a "seamless" assessment and display their results in tandem in a single user-friendly aggregate report; (2) obtain preliminary estimates of item usage, respondent burden (number of items required and administration times), range of levels measured (ceiling and floor effects), and score accuracy in comparison with a full length survey; (3) conduct preliminary evaluations of the acceptance of CAT administrations relative to full length questionnaire; and (4) conduct preliminary evaluations of the usefulness of the prototype aggregate report. The product of Phase I will be a prototype comprehensive ASTHMA-CAT with preliminary evidence regarding feasibility, acceptability, and likely empirical performance. In Phase I1, we will "marry" the new asthma-specific CAT with item pools for generic CAT forms (based on SF-36 and other widely-used HRQOL measures) to create a single comprehensive system. A substantial advantage of our approach in Phase II is the ability to utilize IRT models to "cross-calibrate" the new metrics with scores from current widely used asthma-specific and generic impact tools to enable meaningful comparisons of results. ASTHMA-CAT software, programmed to be fully operational on the Internet and PC-compatible in Phase II, will facilitate clinical research and improve assessment methods for use in clinical practice. Output will be evaluated in terms of reliability, validity and precision of scores. By greatly lowering data collection costs, reducing respondent burden, eliminating "ceiling" and "floor" effects and increasing the precision of individual patient scores, routine monitoring of HRQOL may become feasible as a clinical tool among asthma sufferers and patients with other chronic illnesses.