The Associated Press-Viacom Survey of Youth on Education by Stanford University was conducted by GfK Roper Public Affairs & Corporate Communications from Feb. 18 to March 6. It is based on landline and cell phone interviews with a nationally representative random sample of 1,104 adults between 18 and 24 years old. Interviews were conducted with 603 respondents on landline telephones and 501 on cellular phones.
The sample included 253 African-Americans, 100 of whom were an oversample to have a sufficient number to analyze their responses as a group. Results were then weighted so that African-Americans reflected their correct proportion within the total sample.
Stanford University's participation was made possible by a grant from The Bill & Melinda Gates Foundation.
Digits in the phone numbers dialed were generated randomly to reach households with unlisted and listed landline and cellphone numbers.
Interviews were conducted in both English and Spanish.
As is done routinely in surveys, results were weighted, or adjusted, to ensure that responses accurately reflect the population's makeup by factors such as age, sex, education and race. In addition, the weighting took into account patterns of phone use _ landline only, cell only and both types _ by region.
For the African-American sample, the portion from the core survey and the oversample were weighted to reflect the African-American 18- to 24-year-old population on Hispanic ethnicity, educational attainment, region and age within sex.
No more than 1 time in 20 should chance variations in the sample cause the results to vary by more than plus or minus 3.5 percentage points from the answers that would be obtained if all 18- to 24-year-olds in the U.S. were polled.
There are other sources of potential error in polls, including the wording and order of questions.
The questions and results are available at http://surveys.ap.org.