Dual-frame-method

The dual-frame-method describes the telephone, randomly controlled sampling using a combination of landline and mobile phone numbers. As a result, those people who can be reached primarily or only by mobile (mobile onlys) are also included in the sample. In the case of dual frames, the sample is drawn from two frames or selection frames that completely cover the population: fixed network plus mobile. A suitable design weighting is then necessary to combine the two samples.