The domain of clinimetrics is concerned with quantitative methods in the collection and analysis of comparative clinical data, and particularly with improved "measurement" of the distinctively clinical and personal phenomena of patient care. The main requirement for scientific quality in data is a consistent, reproducible process of observation and expression. This requirement can be attained with appropriate attention to basic descriptive activities and to the operational criteria that convert raw descriptions into the variables, categories, and composite aggregates of suitably chosen clinimetric scales. For this work, clinicians will be challenged to "dissect" and stipulate the components of decisions that are now made with unspecified methods or judgments. Clinimetric science provides opportunities for new approaches, new sites, and new personnel in an additional type of clinical investigation that can augment the scientific basis of clinical practice, while rehumanizing the contents of research data and restoring analytic emphasis to the art of patient care.