1. The WageIndicator Web- survey and the online and offline population. Kea Tijdens; Workshop 7, 17:00 – 18:00

2. Surveys Questionnaires –often used method of data-collection for statistical analyses –until 5 years ago: postal, telephone or face- to-face –expensive & much time needed for data- cleaning –problems of non-response –since 2000: Internet used –problems of reaching the offline population

3. 2 types of web-surveys Sampled web-surveys –addresses are randomly drawn from an adequate sampling frame –f.e. postal addresses or registers –then invitation to participate in the survey –sampled surveys lead to data that is representative for the target population, f.e. the labour force Volunteer web-surveys –everybody is invited to participate –a volunteer web-survey leads never to a representative dataset

4. Why is a volunteer survey not representative? 1.access to Internet 2.interest in wage-related items 3.choosing to visit a WageIndicator website from a choice of >million websites 4.willingness and time to complete a questionnaire 5.sufficient quality of Internet-lines to prevent drop-out 6.capable of completing the questionnaire, i.e. literate and key-board skills

5. How getting representative data? Reference survey –conduct a reference survey of the labour force, thus a sampled survey, addressing the online and offline population –Hungary has held a sampled, paper-based survey with interviewers, which allows to weight the web- survey data (provided sufficient web-data) Weighting –apply weighting by comparing the WageIndicator data to Labour Force Survey data, provided that this data is representative, reliable and recent –Spain and NL have weighted the dataset taking data from their national Labour Force Survey –for the purpose of weighting, USA has a few questions that are similar to the US Labour Force Survey questions

6. Reaching the off-line population For conducting a reference survey –a random sample of the labour force For interviewing any special target group in the labour force –the workers in a company, f.e. in a MNE –the population of a neighbourhood –the visitors of a meeting or a course –any group in the informal labour force –any occupational group, f.e. street venders (this is particularly great for the number of occupations in the salary check)

7. Reaching special groups Webmarketing –for example women by means of a special Women’s WageIndicator website Email actions –for example IT staff in India Interviewing illiterates –if the chance of illiterates is high in a particular occupation, the face-to-face method is better to be used –face-to-face interviews with trained interviewers is recommended

8. Methods for special actions-1 Face-to-face interviews –interviewers using laptops & SPSSPC+ questionnaire versions, provided by the NL team –interviewers using print versions of the questionnaire Paper-based interviews –postal questionnaires using print versions of the questionnaire –hand-out print versions, returned by mail or collected afterwards –questionnaires are printed in a magazine and returned by ordinary mail

9. Methods for special actions-2 Computer-based interviews –respondents using computers in a training room or trade union office, using a SPSSPC+ version or a special web-version of the questionnaire (NL team can make one for you) –using an email campaign or web-marketing, with invitations to complete a special web version of the questionnaire, using a web-link Telephone interviews –with invitation letter, f.e. sampled from postal addresses –without invitation letter (random dialling) –telephone interviewers use a SPSSPC+ version or an allocated web-version

10. Special actions & the questionnaire What can the NL team do for you? –printable questionnaires for employees, self-employed, unemployed, etc. –SPSSPC+ questionnaires for computer- based surveys –create a web-link to the questionnaire –in all cases the data-intake in the special action can be identified in the data (category)

11. Special actions & the national team use the short or long questionnaire in case of the long questionnaire, discuss is questions should be switched off, when not appropriate for the target group NOTE: new questions are costly in case of paper-based questionnaires –print the questionnaires –distribute them –organise the data entry in SPSSPC+ –send the SPSSPC+ batch to NL by email in case of computer-based questionnaires –distribute them –send the SPSSPC+ batch to NL by email

12. Special actions & the data the data is identifiable added to the existing national dataset all data, including the special actions, will be used for the national Salary Check NOTE: at least 50 respondents per occupation are needed for a Salary Check calculation for any occupation (also in case of reference surveys)