Census Overlay samples are used to maximize a specific demographic or economic characteristic of the population you want to interview. The Census Overlay geographical frame is made from Dissemination Areas (DAs) in Canada and zip codes in the US that are above a given threshold for the chosen characteristic. The sample is then selected randomly from all phone listings in the resulting list (frame) of the DAs or zip codes.
For instance: “Select phone listings from zip codes within the state of Florida, where the percentage of households with children under 18 is above X%”. Professionals call these “convenience samples”.
Unfortunately numerous practitioners are taken in by claims of “targeted samples”. They’re led to believe that they can apply statistical methodology based on equal probability samples to their results. Unfortunately there are no such miracles available.
A Census Overlay sample can be very useful when applied carefully and only when it is necessary to improve on low incidence rates and when no other appropriate frames are available.
For more details on Census Overlay sample please refer to the PDF document in the Resources section on this same page.
Contact us today to order your sample!