Collaborations like this—not just CSES, but also the World Values Surveys and the various Barometer series—have been increasing in number in recent years. As these endeavors become more widespread, it may be useful to look back at our experience and note some of the issues we have had to address in setting up the CSES project:

• Importance of central infrastructure. Though the bulk of the work is done in the participating surveys, some central infrastructure is necessary in order to process the donated surveys, check them for internal consistency, add contextual variables on national political institutions, work with less-experienced survey teams, maintain the central repository and website, and so forth. Our project suffered for the first few years from an underfunded, and therefore less than fully satisfactory, central support structure. From the start we maintained a staff for support at the National Election Studies project at the University of Michigan, but for the first few years it was maintained on a hand-to-mouth basis by small grants from Michigan and the University of Minnesota. Since 2001, with funding from the National Science Foundation, things have gone well.

• Keeping the drop-in module short. Since we rely on the generosity (and enlightened self-interest) of participants to provide space in postelection surveys for our module, we must not abuse their hospitality. It is hard to squeeze multiple research concerns into a fifteen-minute segment, but we have been pretty ruthless in avoiding question-creep.

• Mode.  Inevitably, the participating studies vary as to interviewing mode, from face-to-face interviews to mailed questionnaires. All we can really do about this is to document survey administration in a good deal of detail, and include that information, coded in usable ways, in the dataset.

• Standardized questions. Although we design a uniform module and ask participants to use it as a drop-in in their surveys, a number of participants choose to modify certain questions. Just as one example, left-right placement of parties is nearly meaningless for respondents in Korea and Taiwan, and though the investigators there have generously included the question in their surveys, they have reported that it increases respondents’ fatigue and hostility. In several instances, participating surveys have unilaterally made changes in questions. (For this reason, among others, the notes to the CSES codebook are a good deal longer than the codebook itself.)

• Missing variables. In a number of instances, participants have also simply dropped certain questions from the module, which creates missing values for those variables.

• Language and comparability. Crossnational research always must deal with problems of translation and comparability. We do not have funds to provide central translation facilities, so we depend on our collaborators to translate the planning committee’s module into their national language, and to provide us with an English-language version of their codebook. The Cadillac for translation, of course, is back-translation. In a few instances, participants have done this, but most of the time simple translation has been used. We do make available on the CSES website each collaborator's original survey instrument in the original language, so that those using the data can check directly on how a question was asked.