The Associated Press-NORC Center Poll on energy efficiency was conducted from March 29 to April 15 by the AP-NORC Center for Public Affairs Research. It is based on landline and cellular telephone interviews with a nationally representative random sample of 1,008 adults. Interviews were conducted by NORC at the University of Chicago and included 752 respondents on landline telephones and 256 on cellular phones.
The poll was made possible by a grant to the AP-NORC Center by the Joyce 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, cellphone only and both _ by region.
No more than 1 time in 20 should chance variations in the sample cause the results to vary by more than plus or minus 3.1 percentage points from the answers that would be obtained if all adults 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://www.apnorc.org.