Sample design
Our consulting services on survey statistics and sampling
Probability samples
Probability samples provide a basis for drawing conclusions about the target population. The decisive factor here is that each unit (such as individuals or households) must have a known and positive probability of being included in the sample. We can advise you on simple and complex random samples and discuss the best approach for your research question.
Non-probability samples
Non-probability samples are samples that are drawn non-randomly or deterministically. These include quota samples and the (self-)recruitment of respondents, for example on websites or in social networks. The latter in particular is being used more and more frequently in line with the increasing use of online surveys. We advise you on the use of non-probabilistic samples for your specific research questions, discuss potential uses and pitfalls, and show you concrete options for action.
Cognitive pretesting
Empirically assess the comprehensibility and validity of questions in-depth
Sampling
We draw telephone samples and complex samples for you
Weighting and analysis of complex data
We perform weighting, imputation, or nonresponse bias analyses for you
GESIS survey guides
Practical guidelines on survey methodology topics
SQP - Survey quality predictor
Estimate the measurement quality of questions using meta-analysis
Meet the Experts - Season 1: Survey Methodology
Recorded lectures from our "Meet the Experts" series
QuestionLink
Harmonization of questions for selected constructs with recoding scripts and an R package for your own projects