December 12, 2006
Gallup's Newport & Jones on The Gallup Panel
(A post by Mark Blumenthal last week discussed results from a Gallup "panel" survey. Today, Frank Newport and Jeff Jones of the Gallup Organization respond with a Guest Pollster Corner piece that provides more information on the Gallup panel.)
The Gallup Poll Panel is a very large probability-based random sample of 18+ adults, used as the basis for a number of commercial and public opinion research projects. All members are recruited using the same random digit dial (RDD) methodology that is the basis for all "normal" national Gallup polls. The panel currently consists of over 37,000 households and over 54,000 individual members. Recruitment is conducted on an ongoing basis.
While the Gallup Poll Panel was developed primarily for commercial purposes, it is used as the basis for conducting occasional Gallup Poll studies. These Gallup Poll studies in essence are based on a random sample of a larger random sample. All interviewing is conducted by phone using standard Gallup Poll techniques. National samples drawn from the Gallup Poll panel are selected randomly, are demographically representative of the U.S. adult population, and are weighted on the back end to adjust to known population parameters, as we would any RDD poll. The Gallup Poll Panel sample is thus a projectable random sample of the adult population of the United States.
Before initiating the use of the Panel for Gallup Poll studies, Gallup conducted several carefully controlled experiments, fielding the same exact surveys at the same time using the panel sample and the standard RDD sample. Analysis showed very few substantive differences in the frequency distribution of results between RDD and panel. To the extent that there were differences, they were almost always within the margin of error (the one exception concerns asking knowledge questions; panel members seem to consistently score higher on these than RDD respondents). (For more information).
Gallup monitors very carefully the use of the Panel as the basis for nationally projectable samples, and will continue to do so in the future.
Frank Newport and Jeff Jones
The Gallup Poll
By Guest Pollster on December 12, 2006 2:10 PM | Permalink