Selection error in single- and mixed mode surveys of the Dutch general population

Abstract

This study compares the extent of selection error (non-response and coverage error) evoked by the four major contemporary modes of data collection (face to face, telephone, mail and Web) and three sequential mixed mode designs (telephone, mail and Web with face-to-face follow-up) for the case of the Dutch Crime Victimization Survey. Sociodemographic characteristics and target variables from the survey serve as benchmark variables. A special two-wave experimental design allows studying design differences in selection error on Crime Victimization Survey variables independently from differences in measurement error. Despite large differences in response rates, only small or no differences in selection error between the four single-mode designs are found on both types of variable. We observe cases when the error is enlarged or mitigated in the mixed mode designs despite the fact that the designs yielded large response increases. Our results question the use of response rates to motivate the choice of mode and use of mixed mode surveys.