There are occasions in research where it becomes necessary to weight data in order to reduce as much bias as possible and to be able to generalize findings to a specific population. In telephone survey research, design weights are often employed to reduce bias correcting for differences in the probability of selection due to non-response and non-coverage errors. By taking into account the number of landline phones, the number of adults in each household, the number of available records, and the number of records selected within each geographic strata and density strata these errors can be drastically reduced.
