Presentation at Nonresponse Workshop, Copenhagen, 2002

1. Reasons for unit and partial nonresponse in Web Surveys Vasja Vehovar, Gašper Koren, Katja Lozar Manfreda University of Ljubljana

4. Participation in Web surveys

9. Nonresponse process in Web surveys is extremely structured

12. Evaluation surveys RIS2001 Web Survey 2 telephone surveys and 2 web surveys

13. Telephone evaluation Yes (10%) No (90%)

14. Telephone evaluation (n=5016) Yes (10%) No (90%) No 67% / 7% Yes 33% / 3%

15. Telephone evaluation (n=5016) Yes (10%) No (90%) No 67% / 7% Yes 33% / 3% No 25% / 1% Yes 75% / 2%

16. Telephone evaluation (n=5016) Only first few Q 13% I answered part of the Qnaire 33 % I answerd whole Qnaire 63% Yes (10%) No (90%) No 67% / 7% Yes 33% / 3% No 25% / 1% Yes 75% / 2%

17. Web evaluation (n=349) No 43% Yes 57%

18. Web evaluation (n=349) No 43% Yes 57% No 22% / 13% Yes 78% / 44%

19. Web evaluation (n=349) No 43% Yes 57% No 22% / 13% Yes 78% / 44% No 8% / 3% Yes 92% / 41%

20. Web evaluation (n=349) Only first few Q 10% I answered part of the Qnaire 19 % I answerd whole Qnaire 75%

21. Reported Qnaire F low

22. Nonresponse proces

26. Socio-demographic factors

27. Influence on nonresponse process

30. Evaluation – e-Mail invitation Telephone (n=1690) No 97% Yes 3%

31. Evaluation – e-Mail invitation Telephone (n=1690) No 97% Yes 3% No 71% / 2% Yes 29% / 1%

32. Evaluation – e-Mail invitation Telephone (n=1690) No 97% Yes 3% No 71% / 2% Yes 29% / 1% No 37% Yes 63%