Recent technological developments have increased the use of non-questionnaire data within surveys: the universal presence of computing devices such as smartphones, intelligent sensors and smart cards and the increasing awareness of biological constraints and genetic factors for human behavior. This chapter explores some of the techniques available for enhancing surveys with non-questionnaire data. Enhancing surveys with additional measurements will only increase non-response problems if the additional measures do not reduce respondent burden. Enhanced surveys will be more successful if the data collection is done by an institute with a high reputation or in panel studies, in which respondents have repeated contact over years to the same institute or even the same interviewer. The chapter concludes that the enhancing surveys with objective measurements will improve data quality and the amount of information available, but it will also change the social conditions of survey interviewing with impacts on non-response, measurement error, social desirability and data sharing.