The use of sampling procedures may make it necessary to apply weights to produce accurate statistical results. Describe here the criteria for using weights in analysis of a collection. If a weighting formula or coefficient was developed, provide this formula, define its elements, and indicate how the formula is applied to data.
<weight>The 1996 NES dataset includes two final person-level analysis weights which incorporate sampling, nonresponse, and post-stratification factors. One weight (variable #4) is for longitudinal micro-level analysis using the 1996 NES Panel. The other weight (variable #3) is for analysis of the 1996 NES combined sample (Panel component cases plus Cross-section supplement cases). In addition, a Time Series Weight (variable #5) which corrects for Panel attrition was constructed. This weight should be used in analyses which compare the 1996 NES to earlier unweighted National Election Study data collections.</weight>
<weight>
<concept>PropensityWeighting</concept>
The weight was determined using the online opt-in sample, the entire population of a synthetic dataset, and a statistical model to estimate the probability of a case occurring in either the synthetic or opt-in dataset.
</weight>