Source and Accuracy Statements

Data presented in this issue of OmniStats are from the February 2002 BTS Omnibus Household Survey. Data for the survey were gathered from approximately 1000 randomly selected telephone households. The response rate for the February 2002 survey was 46.2 percent. The survey has a margin of error of plus or minus two percent. The data are weighted to allow inferences about the noninstitutionalized population, aged 18 years or older who are currently living in the United States. Because the data come from a sample, they are subject to both sampling and nonsampling error. Sampling error may affect the reliability of an estimate. Nonsampling error can affect both the reliability and accuracy of an estimate and is more difficult to measure. The most general categories of nonsampling error are coverage error, nonresponse error, response error, processing error, and estimation error. For additional information about the survey, please contact Liz Grossman, liz.grossman@bts.gov. Press contact: Dave Smallen, david.smallen@bts.gov.