Household surveys are moving from interviewer-administered modes to self-administered modes for data collection, but many households do not accurately follow within-household selection procedures in mail surveys. In this article, we examine accuracy of within-household selection using an oldest adult/youngest adult method in web, mail, and mixed-mode surveys. The frame for this study comes from a telephone survey conducted with Nebraska residents in which the oldest adult/youngest adult method is used to select the initial respondent. One year later, these telephone participants are followed up using identical household selection methods. This article examines characteristics of people who followed the selection procedures compared to those who did not.