An important component of high quality data is the completeness of the gathered data. Complete response consists of 3 specific factors: (1) sample mortality (the loss of respondents from the initial sample); (2) item nonresponse; and (3) detail given to open-ended items. Responses to the personal interview among Mexican American migrants were evaluated to determine whether high quality data can be obtained through personal interviews within the migrant culture. Mexican American migrants were interviewed during a migrant educational recruitment program conducted in northeast Indiana during the summer of 1974. Migrants were enumerated and then selectively interviewed at the harvesting site. Respondents included 95 parents and 71 children who completed 2 different interview schedules. The overall amount of nonresponse was considered by the respondent's age and sex and by the item content (whether demographic or perceptual). Among the findings were: (1) sample mortality was less of a problem than expected; (2) item nonresponse varied with the respondent's characteristics and the nature of the item; (3) numerous significant differences in nonresponse occurred for both groups, and were comparatively consistent, when the personal interview was used; and (4) due to lack of heavy probing, detail given to open-ended items was minimal for both groups. (NQ)