Errors in Survey Data

Errors in Survey Data All survey data are subject to error; errors can arise from innumerable, often unexpected, sources. Errors can be generated during the planning stage of a survey, more errors can be created during the later stages of data recording and processing. Indeed, we cannot list all the ways in which surveys can go wrong. It is possible, however, to raise our awareness of the problem by focusing on two broad categories of error, random error and systematic error (or bias).