Verification

Within survey research, one of the meanings of verification refers to efforts that are made to confirm that a telephone or in-person interview was actually completed with a particular respondent. Within this context, verification is one of the techniques used to guard against interviewer falsification. Such verification often is done via telephone even if the interview was done in person. In most cases a small number (e.g., less than five) of randomly selected completed interviews of all interviewers are verified by having a person in a supervisory position contact the respondents and verify that they were, in fact, interviewed by the interviewer. In other instances, interviewers who may be under observation for previous interviewing infractions may have a greater number of their interviews verified. Oftentimes, interviewers are instructed to tell respondents at the end of an interview that someone may contact them to verify that the interview was completed.

Other meanings of verification, within the context of survey research, concern efforts that researchers sometimes make to verify whether a respondent's answer to a key variable is accurate. These procedures include so-called record checks in which the researcher gains access to an external database (such as those assembled by various government agencies) that can be used to officially verify whether the answer given by a respondent is correct. For example, in a survey conducted of voting behavior, if respondents are asked in a survey whether they voted in the past election, then researchers could go to public election records to learn if a given respondent did or did not vote in the last election, thereby verifying the answer given in the survey. However, in this entry, it is the former meaning of the term verification that is addressed.

In theory, informing interviewers that some of their completed interviews will be verified is assumed to motivate them against any falsification. However, little empirical work has been done to test this assumption. Nevertheless, many clients expect this will be done, and as such, verification is a process that many survey organizations build into their contracts. Of note, verification should not be confused with interviewer monitoring, which is a process used in real time to observe the behavior of interviewers as they interact with respondents in (a) gaining cooperation from the respondents and (b) gathering data from them.

Verification serves additional purposes beyond its primary purpose of confirming whether or not a given interview was conducted. In addition, a systematic and routine verification process provides information that a survey organization can use to evaluate the job performance of individual interviewers. For example, when respondents are contacted to verify a completed interview, they also can be asked a few additional questions, at very little additional cost to the survey organization, to help evaluate the quality of the interviewer's work. A system of routine verification can also serve as a check on the quality of the interviewer monitoring system a survey organization has instituted, as verification is a fail-safe approach to detecting falsification, which ideally should be detected via on-the-job monitoring.

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