1. Internet data collection in the LFS Danish experiences
Nordstat, August 2010

2. Lessons learned from pilot test
Outline
Lessons learned from pilot test
Experiences from full scale CAWI data collection

3. Background The Danish LFS has individuals as sampling unit
Until 2010 selected household variables was collected via proxy in the final interview round
Requested by Eurostat to fully comply with regulation no. 577/98 from Q1 2010

4. Discussions on collection modes:
Preparations
Discussions on collection modes:
How much CATI vs CAWI?
How many reminders?
The design?

5. The Pilot Two groups: Aldi vs. Irma
712 household members in each group
split over two reference weeks
two weeks interview period
Aldi: baseline with no reminders and no CATI
Irma: Two phone reminders and optional CATI

6. What was learned: Pilot – the results Reminder needed
Indirect effect (threat effect)
Direct effect
2nd reminder not necessary
A 2 week interviewperiod is sufficient

7. Number of web-based int. accumulated, reference week 40

8. Age related effects More lessons
CATI option important for older age groups
Effect of reminding procedure, relatively larger among younger age groups

9. Response-rate by age and data-collection method

10. The Final Setup Important to have time to evaluate pilot thoroughly
Going full-scale: Not a big problem
4th panel households selected
Only one interview for household members
1 telephone reminder
Letters sent Saturday, received Monday

11. Response rate Q1 2010

12. Response rate issue – complete households
Only complete households are usable
6138 households in Q1 sample
2940 completed interviews with all household members
360 of these households deleted because of reference person

13. Quality examined - NACE

14. Quality examined - ISCO

15. In-depth quality analysis Coding of NACE and ISCO
Further work
In-depth quality analysis
Coding of NACE and ISCO
Analysing the mode effects of CAWI in core-LFS

16. Thank you! Nordstat, August 2010 Michael Frosch mif@dst.dk
Sammy Lauritsen