The Associated Press-GfK Poll on the attitudes and opinions of Japanese was conducted by GfK Roper Public Affairs & Corporate Communications from July 29 to Aug. 10. It is based on landline telephone interviews with a nationally representative random sample of 1,000 adults.
The survey sample frame includes Japanese households that have at least one fixed telephone landline, or about 91 percent of all Japanese households, and represents the national population of Japan age 18 and older living in the 47 prefectures (states).
Digits in the phone numbers dialed were generated randomly to reach households with unlisted and listed numbers. The sample was stratified by region with targets set for the number of complete calls per region.
Interviews were conducted in Japanese by live interviewers in a Tokyo-based telephone interviewing center.
As is done routinely in surveys, results were weighted, or adjusted, to ensure that responses accurately reflect the population's composition. That included Japan's mix by age within sex, city or region, and by education.
No more than one time in 20 should chance variations in the sample cause the results to vary by more than plus or minus 3.8 percentage points from the answers that would be obtained if all adults in Japan 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.ap-gfkpoll.com.