The specific hypotheses tested in the cross-sectional prevalence study were: 1) greater validity of self-perceived symptoms was associated with less functional morbidity from asthma; 2) specific psychological and asthma-related determinants affected the sensitivity and specificity of symptom perception in children with asthma; 3) perception of respiratory symptoms was a measurable characteristic that could be evaluated in terms of reliability and validity; 4) perceptual accuracy in a natural or clinical setting was significantly related to perceptual ability measured in a laboratory.