The objective of the ESS sampling strategy is the design and implementation of workable and equivalent sampling plans in all participating countries. Sampling on the ESS is guided by the requirements outlined in the Survey Specifications and the following key principles:
- Samples must be representative of all persons aged 15 and over (no upper age limit) resident within private households in each country, regardless of their nationality, citizenship or language
- Individuals are selected by strict random probability methods at every stage
- Sampling frames of individuals, households and addresses may be used
- All countries must aim for a minimum 'effective achieved sample size' of 1,500 or 800 in countries with ESS populations of less than 2 million after discounting for design effects
- Quota sampling is not permitted at any stage
- Substitution of non-responding households or individuals (whether 'refusals', 'non-contacts' or 'ineligibles') is not permitted at any stage
You can find out more about the ESS sampling principles in the current ESS Sampling Guidelines.
Sampling Expert Panel
Each National Coordination team is responsible for producing a sample design that adheres to ESS sampling principles and is suitable for implementation in their country. They are supported in this task by a member of the ESS Sampling Expert Panel who is assigned to assist them. The Panel is currently in the process of being renewed.
For further information on the ESS sampling principles and country-specific sampling designs, please contact the ESS ERIC Headquarters.
Sampling Design Data Files
The sampling design has a major influence on the variance of estimators, and features such as multi-stage sampling, selection of clusters and stratification should be taken into account when producing variance estimates. Details on the sampling designs used in each ESS Round can be found in the ESS Data Documentation Report for the respective round. Information on stratification and clustering of ESS data is made available in the published Sample Design Data Files (SDDFs).
For further information on the SDDFs, please contact the ESS ERIC Headquarters.