I was recently watching a review of Schindler's List by Siskel and Ebert here, and in the opening minute of the video, Gene Siskel quoted a New York Times story which claimed that "over 1/3 of adult Americans didn't think the Holocaust even occured." This seems startling; did this many Americans really not believe the Holocaust in the early-1990's, and if so, what effect did Schindler's List have on them, if any?
The New York Times story likely referenced a poll done by the Roper Organization in 1992. As this Harvard University study (pg. 11) points out, there was a problem with how the question was addressed to respondents. The question read:
Does it seem possible or does it seem impossible to you that the Nazi extermination of the Jews never happened?
The use of the double-negative apparently caused a lot of confusion, with up to 20% of respondents saying that the Holocaust might never have occurred.
After figuring out the problems with the question, the organization rephrased it and the percentage of respondents saying the Holocaust might not have happened went down to 1%.