Three studies were conducted to examine factors which affect lay observers' judgments about peers who express illness complaints. In the first study, brief scenarios describing a hypothetical patient suffering from a sore throat were presented to 118 college students. The results revealed that subjects were less likely to regard the patient's sore throat as legitimate when there was negative evidence of an infection, when his college workload was heavy, and when his love-life was unhappy. Even when subjects knew the patient's symptom had an organic cause (Positive Infection evidence), they regarded the symptom as less legitimate when it was compounded with psychological or social stress. Impressions of the patient and treatment recommendations were also analyzed. In an attempt to replicate the pattern found in the Positive Infection groups, a follow-up study was conducted in which scenarios were modified. The results showed the pattern of legitimacy ratings to be quite similar to the pattern in the original study. A third study aimed to present patient information in a richer and more realistic format than the scenario approach. Preliminary analyses suggest that subjects picked up on manipulations of infection evidence, workload, and love-life, and that these influenced their legitimacy ratings, treatment recommendations, and impressions much as in the original study. The issue of diagnostic test credibility was also examined in the third study. (NB)