Investigation of these objectives used a study of validity of self-perception of symptoms in relation to clinical status. Children aged 8-15 made subjective estimates of their asthma severity immediately prior to pulmonary function testing at multiple times while they lived either at a summer camp for children with asthma or a long-term asthma treatment center. The correspondence between subjective and objective measures of pulmonary function in the clinical environment were compared with results obtained in a laboratory using threshold detection of added resistive loads. The sensitivity and specificity of asthmatic children's self-assessment of symptom state were quantified and related retrospectively to risk of functional morbidity. Cognitive abilities, anxiety level, tendency toward repression, locus of control, and familial factors were investigated regarding their role as determinants of sensitivity and specificity of symptom self-perception as a measure of pulmonary function. The stability of individual patterns of self-perception were studied longitudinally with annual repeated evaluations among those children who returned to camp or were rehospitalized.