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You have not found the information you were looking for? Please have a look at our list of most frequently asked questions.

1. How can I apply for the CILS4EU data?

You will find a description of how to apply for the data on the webpage of the GESIS Data Archive for the Social Sciences - just click here, enter "CILS4EU" in the search field and choose "Research data" as a filter. All available versions of the CILS4EU and CILS4EU-DE data will be listed there and you can decide which version you want to apply for.

2. Should I apply for the full version or the reduced version of the data set?

Of course, there is no general answer to that question. However, we want to emphasize that the reduced version is a very informative and workable data set. Our codebook, specifically Appendix F (available in all codebooks, codebook of wave 1 linked as an example) gives you an excellent overview of all variables that are not included or modified in the reduced version. Please take a look to decide whether the information you need for your analyses is included in the respective reduced version data set.

3. I want to learn more about the CILS4EU data. Are there any opportunities or conferences to get to know the data?

We do not only provide our users with data, we also organize events where we introduce them to the structure and specificities of it. Have a look at the "Announcements" tab in the menu under "Events". You can also find the slides of our 2023 Meet the Data Workshop to download here.

4. Is it possible that a variable is completely missing in the data set I have been delivered?

Before publishing our data sets and sharing them with researchers all over the world, CILS4EU(-DE) data are checked for mistakes in an extensive procedure. Please check the codebook(s) included in your data package for information about the reason for a missing variable and/or missing values. For example, some items might not have been asked in all four countries or not in certain waves.

If this remains an issue, please approach our contact persons at the GESIS Data Archive for the Social Sciences in Cologne:

GESIS, Team Data Service
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Phone:  + 49 221/476-94-420

5. I discovered that variable names sometimes end in specific letters (e.g., generationG) in the data set . What do these letters mean?

Generally, one of these letters attached to the name of a variable indicates that this is a variable that has been somehow adapted throughout the data cleaning process. This overview table offers more information on the meaning of the different variable-name-endings:





Generated variables

> The generational status variable generationG was generated using information provided by the child about his or her country of birth and age upon arrival as well as information provided in the parental interview about the biological parents’ countries of birth as well as the grandparents’ countries of birth.


Country-specific variables

> Due to divergent educational systems in the four CILS4EU countries, categories for idealistic educational aspirations differ sharply between countries. Therefore, a country-specific variable y1_edasp1CS is included in the data set that contains a total of 20 categories for every answer possibility in the four countries.


Harmonized variables

> Idealistic educational aspirations y1_edasp1H were harmonized for England, Germany, the Netherlands and Sweden. This means that educational degrees were made comparable in the respective harmonized variables by combining several categories. The harmonized variable distinguishes “no degree”, “degree below upper secondary school”, “degree from upper secondary school and “university”. Original answers are still available in the country specific variables (see above).


Reduced-version variables

> Complete information on the respondent’s concrete country of birth y1_cob is not available in the reduced version of the data. Instead, we offer a reduced version of this variable y1_cobRV, which distinguishes whether the respondent was born in the survey country or not. This variable is also included in the full version of the data.


6. The data contains negative values. What is the meaning of these missing codes?

CILS4EU data allow to distinguish easily between several different kinds of missing values. This missing values coding scheme is used in each data set and does not change over the waves. The meaning of the negative values is the following:





Don’t know

Only if this option was provided in the questionnaire


No answer

No box ticked/no answer given


Not applicable

Not answered due to filter question


Question not asked

Not asked in a country/mode


Other missing

Answers that could not be coded, fun answers


Interrupted Interview

Only for telephone and online modes


Not available in reduced version

Answers not available in the download version


7. I want to publish my work with the CILS4EU data. Do I have to cite it in a specific manner?

Yes, you should indeed follow our citation guidelines for CILS4EU data and documentation. Please have a look at this page for more information.


8. To whom should I address further questions or feedback related to the data sets or to the data application procedure?

Please feel free to approach our contact persons at the GESIS Data Archive for the Social Sciences in Cologne, Germany.

GESIS, Team Data Service
Diese E-Mail-Adresse ist vor Spambots geschützt! Zur Anzeige muss JavaScript eingeschaltet sein.
Phone:  + 49 221/476-94-420