Archiving Data and Documentation of the ISSP at GESIS-ZA

Contents

• Introduction
• Time Schedule and Deadlines
• Data Quality and Filters
• What constitutes an ISSP deposit?
• Technical Formats for Data Delivery

Introduction

The first ISSP module - Role of Government I - was conducted in 1985 in six countries. Since then, the ISSP was extended continuously, both in terms of modules and of member institutions.

From the beginning, the Zentralarchiv, now GESIS-ZA, has served as official archive of the ISSP. Since 1997 the ZA is supported by the Spanish ISSP partner ASEP in Madrid. The central task is to produce international data sets with appropriate documentation (codebooks). When dealing with international comparative data, data sets and documentation must be seen as two sides of the same coin. Even though every effort has been made to produce comparable data in each country, and even though GESIS-ZA works closely with member countries to clarify and harmonise deviations from the basic coding schemes, there still remains a remarkable amount of country specific peculiarities in the final, international data set. These country specific peculiarities have to be documented in order to supply secondary analysts with vital information.

The format of the data and documentation supplied by each member country to GESIS-ZA should be as close to the format of the integrated international files as ever possible. This may sound simple, but experience has shown that deviations are frequent. And even seemingly minor deviations from the expected standard cause time-consuming efforts when combining the national data sets.

Therefore, the main task of this manual of Archiving Rules is to define standards and formats for data and documentation of the ISSP modules to be deposited at GESIS-ZA. 

Time Schedule and Deadlines

The data and the complete documentation should have arrived at the archive by September 1st of the calendar year following the year of the data collection for the respective module (e.g. data from the ISSP 2003 module are to be completely archived by September 1st, 2004 at the very latest). A data set delivered to the archive can be only regarded complete if it is accompanied with sufficient documentation (coding information plus study description plus population characteristics plus a blank questionnaire).

All data sets being archived by this time (September 1st) are guaranteed to be integrated into the module. This international file will usually be made available in a preliminary version at the following annual ISSP conference. Comments and corrections from ISSP participants can be incorporated right after the conference. The complete international data set and full documentation will then be made publicly available within a few months.

If single countries provide revised versions of data sets which have been archived before, these revisions can only be incorporated if delivered within the time-schedule and if the deviations from previous versions are exactly documented.

Country data sets which are not completely deposited before April 15th of the second year after the module's year can definitely not be included in the final integrated file.

This schedule was agreed upon during different ISSP conferences and is part of the ISSP Working Principles. It must be seen in the light of the actual experiences. Changes in these time perspectives caused by changing conditions will be discussed and decided at the ISSP meetings.

Data Quality and Filters

Some of the variables (especially some background variables) are subject to filtering conditions, e.g. "Occupation of spouse/partner". It should be documented clearly for which respondents this question applies: for those married; only for those who are married and live together; for those who have a permanent partner ...

The questions behind this demand are:

• How far can consistency checks carried out at GESIS-ZA go?
• What is the minimum acceptable level of data quality?

It is obvious that the highest level of consistency should be reached, because the quality of analyses depends on the quality of data. However, it is also obvious that each additional bit of quality consumes a multiple of processing time. The extent of this additional effort depends on how consistent the original data is and how well the filtering conditions are documented. 

What constitutes an ISSP deposit?

In many cases, the ISSP questionnaire is part of a larger survey. However, the data set supplied to the archive should only contain the variables from the ISSP questionnaire (including the optional variables of such a module, if they have been asked, and of course including the standard background variables).

The coding information for the complete ISSP data set (at least: variable names and labels, value labels and variable positions in the data set (data list) for each variable) should come together with the data set and should be all in English. The data should be supplied in SPSS format (portable file). In many cases, the necessary information is not described sufficiently by the SPSS 'label information'. In these cases (e.g. open-ended questions, derived variables etc.), additional detailed documentation is absolutely necessary!

A blank questionnaire as used during the field-work also belongs to the documentation of the study and will be archived as well. It would be much appreciated if in addition to the mandatory hard copy version an electronic version (PDF file, exact MS Word printing master of the questionnaire, or scan image) could be supplied. A complete list with links to the required document templates can be found here.

Technical Formats for Data Delivery

• Media

The data deliveries can be made on all common media, that is, by CD-ROM, by e-mail to isspservice<at>gesis<dot>org or in special cases by FTP upload.

• Data Format - SPSS

SPSS portable files with full documentation (VARIABLE LABELS and VALUE LABELS for all variables) according to the SPSS or XML setup circulated in advance for each module. The ISSP Standard Background Variables should be coded according to the scheme supplied in the respective document.