A general concern with the representativeness of online surveys is that they exclude the "offline" population that does not use the internet. We run a large-scale opinion survey with (1) onliners in web mode, (2) offliners in face-to-face mode, and (3) onliners in face-to-face mode. We find...

Using data from a non-mobile-optimised survey in the UK, this paper compares the quality of survey data from mobile devices with different screen size. The findings suggest that data quality mainly differs between small smartphones with a diagonal screen size of below four inches and larger...

This paper investigates if significant differences exist between online and paper & pencil participants in a quarterly business survey in the German business-related services sector when respondents may freely choose to respond either online or by more conventional methods. It also analyzes the...