Who's There? Comparing Respondents from a Telephone Survey to a Mail Survey

The increasing accuracy and availability of address sampling frames have led researchers in the public and private sector to reconsider mail self-administered surveys as a viable alternative to telephone Random Digit Dial (RDD) studies. Mode effects in surveys have been well documented. One aspect of the effect that is worthy of exploration in the transition of a survey from telephone to mail is whether or not the change in mode draws in a different respondent from the household. The National Household Education Survey (NHES) was conducted by telephone approximately every two years beginning in 1991. As a result of falling response rates and concerns about coverage in the list assisted RDD sample, the survey began a redesign in 2009. The first step in this redesign was a feasibility test of a two-phase mail survey. The NHES consists of a series of rotating modules, most of which are focused on a reference child. Past research has shown that the household informant plays a role in the quality of data collected. As a result of this, telephone interviewers were instructed to ask that the adult in the household who is most knowledgeable about the selected child serve as the respondent. To facilitate response in the household, the mail self-administered questionnaire requested that someone knowledgeable about the child respond; however, the request is likely to be less salient to the respondent in a self-administered survey compared to an interviewer-administered survey. This paper will examine the characteristics of respondents in the phone and mail surveys. Changes in the household respondent could have profound effects on measurement. Understanding differences in who is likely to respond by phone compared to mail can also lead to the development of better contact approaches for mail surveys.