VCS prepares random samples of voters from our voter file. All samples can be printed as lists or delivered as files. Most common delivery is an immediate customer download of the sample from the VCS website. Using this technique a sample can usually be prepared within an hour or so. See reasons why VCS voter samples are the best available.

An extensive demographic analysis is also provided of the voter base and the sample selected. See more information on this analysis along with copies of the reports.

Samples are prepared by following a 'stratified' sampling technique. A skip interval of 'n' is determined to produce the desired number of voters in the sample.The computer then picks every nth voter from the voter file to produce the sample. Samples can also be prepared with 'clusters' of voters. After skipping n voters the computer can then select a cluster of voters at that point, generally from adjacent households. The customer can specify how many voters should occur in each cluster.

VCS has also developed a very powerful technique called "pure phone clusters". Every voter in the cluster has a phone number, but the distribution of the sample over the district is not skewed by areas of higher or lower phone match. See more detailed information on how samples are prepared and formats of lists.

VCS also prepares a more sophisticated form of sample, "predicted electorate random samples" (PERS). These samples involving using different skip intervals in different portions of the electorate according to methodology developed by a group of researchers at the Institution for Social and Policy Studies at Yale University. See more information on PERS samples and how they are prepared.