The SOEP group at DIW Berlin introduced the SOEP-IS panel for short-term experiments but also for long-term surveys that are not possible in the SOEP-Core—for instance, because they require instruments that are not yet well established or that deal with very specific research topics. In addition to Samples E and I from SOEP-Core, which were started in 1998 and 2009, respectively, new samples were drawn in 2012, 2013, 2014 and 2016 to achieve the final number of 5,000 respondents. The annual interviews since 2012 have contained not only questions from the SOEP-Core but also innovative modules, which are selected in a peer-reviewed competition as of the 2013 survey year to identify the "best" research questions. The survey is conducted by specially trained interviewers from the fieldwork organization TNS Infratest Sozialforschung using computer-assisted personal interviewing (CAPI) and is representative for Germany as a whole. Some of the many topics include earnings, employment, education, and health. The international version contains 95% of all cases surveyed.