For a long time, survey researchers have needed more comprehensive and reliable diagnostic tools to understand the components of total survey error. Some of those components, such as margin of sampling error, are relatively easily calculated and familiar to many who use survey research. Other components, such as the influence of question wording on responses, are more difficult to ascertain. Groves (1989) catalogues error into three other major potential areas in which it can occur in sample surveys. One is coverage, where error can result if some members of the population under study do not have a known nonzero chance of being included in the sample. Another is measurement effect, such as when the instrument or items on the instrument are constructed in such a way to produce unreliable or invalid data. The third is nonresponse effect, where nonrespondents in the sample that researchers originally drew differ from respondents inways that are germane to the objectives of the survey.

Defining final disposition codes and calculating call outcome rates is the topic for this booklet. Often it is assumed — correctly or not — that the lower the response rate, the more question there is about the validity of the sample. Although response rate information alone is not sufficient for determining how much nonresponse error exists in a survey, or even whether it exists, calculating the rates is a critical first step to understanding the presence of this component of potential survey error. By knowing the disposition of every element drawn in a survey sample, researchers can assess whether their sample might contain nonresponse error and the potential reasons for that error.

With this report, AAPOR offers a new tool that can be used as a guide to one important aspect of a survey’s quality. It is a comprehensive, well-delineated way of describing the final disposition of cases and calculating outcome rates for surveys conducted by telephone, for personal interviews in a sample of households, and for mail surveys of specifically named persons (i.e., a survey in which named persons are the sampled elements). For this third mode, this report utilizes the undelivered mail codes of the United States Postal Service (USPS) which were in effect in 2000.

AAPOR hopes to accomplish two major changes in survey research practices. The first is standardizing the codes researchers use to catalogue the dispositions of sampled cases. This objective requires a common language, and definitions that the research industry can share. AAPOR urges all practitioners to use these codes in all reports of survey methods, no matter if the project is proprietary work for private sector clients or a public, government or academic survey. This will enable researchers to find common ground on which to compare the outcome rates for different surveys.

Read the full report here.