Drawing of random telephone samples

A total of about 45% of interviews in German market research is currently conducted over the telephone. Since the late 1990s a sampling frame, developed at ZUMA (Gabler-Häder design), has become increasingly popular in Germany which contains both directory-registered and unregistered telephone connections only available via local exchange. This sampling frame is updated biannually.

On behalf of research partners from the university-based social research GESIS will draw samples for nationwide as well as, if needed, regional surveys.

Moreover, in recent years a tendency has been manifested which possibly makes the singular future use of this sampling frame appear insufficient to cover the totality of private households: A growing share of households is solely to be reached via cellular telephones. Therefore, GESIS has been devoting itself to the development of a sampling frame for cellphone samples which will shortly become available.