How the AP-GfK poll on contested conventions was conducted

The Associated Press-GfK poll on a possible contested GOP convention was conducted by GfK Public Affairs and Corporate Communications March 31-April 4.

No more than 1 time in 20 should chance variations in the sample cause the results to vary by more than plus or minus 3.3 percentage points from the answers that would be obtained if all adults in the U.S. were polled.