Important components in understanding response errors in surveys are learning how respondents comprehend questions and how interviewers handle situations where respondents' definitions do not match survey definitions. In most large surveys, survey question wording and question order are standardized and interviewers are trained to be neutral, nondirective and nonbiasing extensions of the survey instrument. The goal of this standardization is to present the same stimulus to all respondents and the underlying assumption is that as long as questions are presented in this manner they will be heard in the intended way and will stimulate valid responses.