The first task of any analyst should be to read the detailed methodology of the survey to be used. This will give you information about how the survey was conducted and provide you with the information needed to assess whether you are happy to use this dataset for the purposes you intend. It is important that any differences evident from your analysis are real and are not simply an artefact of differences in how the surveys were conducted in the participating countries or a result of the questions having slightly different meanings.
It is important to look not only at the design specification but all at any information available about deviations from the design.
The European Social Survey is one of the few surveys to provide information on adherence to the design specification making it easier for the user to be aware of any non compliance or deviations that might affect the results. The detailed methodologies for the various surveys can be found at:
Essential reading on the adherence to the design specification and on methodological tests in the development of the survey are available for round 1 of the European Social Survey at:
In the next section we will look at some of the things to look for in assessing microdata.