The Common Data Set (CDS) is a set of standards and definitions of data items rather than a survey instrument or set of data represented in a database. Each of the higher education surveys conducted by the participating publishers incorporates items from the CDS as well as unique items proprietary to each publisher. Consequently, the publishers' surveys differ in that they utilize varying numbers of items from the CDS.
The CDS initiative is a collaborative effort between publishers and the educational community. More information can be found on the Common Data Set Initiative website.