This paper has three objectives: ( 1) to describe an application of the hypothetical situation in individual and group interviewing; (2) to modify the concept of "illness referral system" as used by several other investigators; and (3) to contribute to the ethnography of Spanish American culture. The data were gathered from 1959 through 1962 on field trips totaling about seventeen months. The summer of 1959 was spent as a participant observer studying the cultural context of health behavior in Abajo (a fictitious name), a village of approximately 600 persons in northern New Mexico. The summers of 1960 and 1961 were utilized to interview acculturated urban migrants and parteramedicas (midwife-health specialists) in or near two cities of 5,000 and 35,000 population within 100 miles of the village. Finally, seven months of 1962 were spent in Abajo investigating factionalism and social structure. Although all of the material gathered on these occasions contributed to the overall understanding of health action systems, the interest here is in the results of using the hypothetical situation technique in individual and group interviews during the summers of 1960 and 1961.