RDD Sample Generation
In this article, we will outline RDD Sample Generation in multiple steps.
Random Digit Dialing, commonly known as RDD, is a cost effective method for generating a representative sample of households with fixed telephones. This process allows us access to hard to reach areas where targeted sampling is tough. RDD sample is available using both landline and mobile contacts and enables us to generate numbers based on area, country or network provider.
Sample Solutions has developed a highly accurate RDD procedure that maintains the representative proportion of the corresponding populations.
RDD Sample generation
The first step in RDD sample generation is to acquire the numbering plan(s) of the area(s). Our sampling frame for landlines includes all residential telephone numbers (including listed, unlisted and non-published numbers) in the defined sample frame for a set of geographic criteria. The system uses a detailed analysis of Phonebook / Commercial listings or databases to generate a sample frame which is compared to the numbering plan for consistency.
In the second step, we generate the raw RDD sample. We generate RDD sample for mobile based on the ratio of provider share in the market or completely random numbers for the landline. This dual frame approach will help minimize non-coverage bias in the sample and make it most representative.
Next, all these numbers need to be filtered for active / non-active numbers where all disconnected numbers are removed from the sample batch. In addition, non-residential numbers are purged from the generated sample. This eliminates the cost associated with interviewers wasting their time on calling nonworking and business numbers thus improving productivity rates.
At the end of the generation process, we are adding necessary strata and quality checks. In the post-processing step, we are also providing oversample at no extra costs for our customers.
If you want a more detailed outline of our RDD Methodology read our whitepaper.
What are the main advantages of RDD sample?
The main advantage of RDD is that it includes unlisted numbers as well. For many developed countries it holds that there is a high telephone ownership rate and thus RDD is a cost-efficient way to get complete coverage of a geographic area.
For all national representative studies, we can provide a turnaround time of 24 hours.