EQLS 2012 - Quality assurance
To ensure high quality of the data, each stage of Eurofound surveys is subject to detailed planning, close monitoring and documentation. Eurofound surveys subscribe to the quality criteria of the European Statistical System (ESS).
In designing the 3rd EQLS, the results of the quality assessment of the 2nd EQLS 2007 and the results of a dataset user survey were taken into account, along with consideration of emerging policy issues.
Quality control measures were included in the technical specification of the survey, and a specific Quality control plan was developed and adopted with the fieldwork contractor. This ensured the application of best practice and establishment of specific quality control targets encompassing all survey phases.
The fieldwork contractor has compiled a Quality assurance report which provides a summary of the quality assurance activities performed during the survey preparation, data collection and data processing. Quality control measures for the 3rd EQLS covered elements from sampling to translation and questionnaire verification to interviewer control and data validation:
- questionnaire verification (pre-tests, pilot interviews);
- questionnaire translation validation;
- sample quality control, including enumeration control (via geocoding and mapping, at least 10% of the PSUs) for countries where registry based sampled were not available;
- checks and approvals of fieldwork materials;
- interviewing verification (CATI, postal or face-to-face back-checks of random 10% of the cases);
- fieldwork visits by Eurofound;
- systematic data validation.
A data editing & cleaning report is also available.
After the completion of the fieldwork, an external quality assessment of the EQLS 2011 was carried out against the quality criteria outlined by the European Statistical System (ESS).