Technical Note The estimates in this release were obtained from a supplement to the October 2010 Current Population Survey (CPS), a monthly survey of about 60,000 households that provides information on the labor force, employment, and unemployment for the nation. The survey is conducted monthly for the Bureau of Labor Statistics by the U.S. Census Bureau. Data in this release relate to the school enrollment status of persons 16 to 24 years of age in the civilian noninstitutional population in the calendar week that includes the 12th of October. Updated population con- trols for the Current Population Survey are introduced annually with the release of January data. Additional information about population controls is available on the BLS Web site at www.bls.gov/cps/documentation.htm#pop. Information in this release will be made available to sensory impaired individuals upon request. Voice phone: (202) 691-5200; Federal Relay Service: (800) 877-8339. Reliability of the estimates Statistics based on the CPS are subject to both sampling and nonsampling error. When a sample, rather than the entire population, is surveyed, there is a chance that the sample estimates may differ from the "true" population values they represent. The exact difference, or sampling error, varies depending on the particular sample selected, and this variability is measured by the standard error of the estimate. There is about a 90-percent chance, or level of confidence, that an estimate based on a sample will differ by no more than 1.6 standard errors from the "true" population value because of sampling error. BLS analyses are generally conducted at the 90-percent level of confidence. The CPS data also are affected by nonsampling error. Nonsampling error can occur for many reasons, including the failure to sample a segment of the population, inability to obtain information for all respondents in the sample, inability or unwillingness of respondents to provide correct information, and errors made in the collection or processing of the data. A full discussion of the reliability of data from the CPS and information on estimating standard errors is available at www.bls.gov/cps/documentation.htm#reliability. Concepts The principal concepts used in connection with the school enrollment series are described briefly below. School enrollment. Respondents were asked whether they were currently enrolled in a regular school, including day or night school in any type of public, parochial, or other private school. Regular schooling is that which may advance a person toward a high school diploma or a college, university, or professional degree. Such schools include elementary schools, junior or senior high schools, and colleges and universities. Other schooling, including trade schools; on-the-job training; and courses that do not require physical presence in school, such as correspondence courses or other courses of independent study, is included only if the credits granted count towards promotion in regular school. Full-time and part-time enrollment in college. College students are classified as attending full time if they were taking 12 hours of classes or more (or 9 hours of graduate classes) during an average school week and as part time if they were taking fewer hours. High school graduation status. Persons who were not enrolled in school at the time of the survey were asked whether they had graduated from high school. Those who had graduated were asked when they completed their high school education. Persons who had not graduated, that is, school dropouts, were asked when they last attended a regular school. Those who were enrolled in college at the time of the survey also were asked when they graduated from high school. Recent high school graduates. Persons who completed high school in the calendar year of the survey (January through October) are recent high school graduates. Recent high school dropouts. Persons who were not enrolled in school at the time of the survey, attended school a year earlier, and did not have a high school diploma are recent dropouts.