Weighting

Weighting involves counting a respondent as either more than one person or less than one person. In the 2012 ANES, the weights are used to correct for a higher or lower chance of a respondent being included in the sample than he or she would have by chance alone. In addition, the weighting attempts to increase the sample's representativeness on demographic characteristics. For the most part, this weighting is transparent — you will not notice that it is happening at all. At times, however, some contingency table marginals or frequency distributions will have fractional respondents — this is because of weighting.