1. What Day of the Week Would You Like to Answer Our Survey? Maria Andreasson, B.A. Laboratory of Opinion Research (LORE) Department of Political Science University of Gothenburg

2. Overview Different weekdays participation rate - after 24 hours - after 6 days - after 8 days and one reminder - after 14 days Respondents preferred day for survey response

3. Laboratory of Opinion Research (LORE) Web survey experiments Panel data Methodological evaluations

4. Panels The Citizen Panel -57,000 opt-in -9,000 probability recruited Non-commercial No incentives The Panel of Politicians -4,000 politicians on national, regional and local level, opt-in The Panel of Journalists -1,700 opt-in

5. Research collaborations Open call for proposals at lore.gu.se

6. Survey design 11,300 pre-recruited members of the Citizen Panel Mix of opt-in (74%) and probability sample (26%) Randomly assigned day of the week for survey invitation (n=1,600/day) Survey invitation Wednesday 15 th -Tuesday 21 st October 2014 A reminder sent after one week

7. Participation rates -Clicking on survey link in email invitation -Excluding email bounces

8. Results: Participation rates after 24 hours (%)

9. Results: Participation rates after 6 days (%)

10. Results: Participation rates after 8 days (%)

11. Results: Participation rates after 14 days (%)

12. Preferred day for survey (%)

15. Difference of preferred day of survey if invitation same day and response within 24 hours (percentage points)

16. Summary Invitation day has significant effects on participation rates after 24 hours - Saturday worst - Early days of the week best No significant effects after 6 days or more Respondents say they prefer surveys on Mondays-Thursdays and Sundays Respondents more positive to receiving surveys on the day they actually receive it Respondents even more positive once they have tried the day, especially Saturday and Sunday

17. Thank you! You can read more at lore.gu.se