Doesn everyone agree that the exit poll results were outside the margin of error?
Yes: overall, and in many states, the exit poll results differed from the official results by beyond the margin of error, overstating Kerry’s performance. (This overstatement is often called red shift, meaning that the “red candidate” Bush did better in the official returns than in the exit polls.) For instance, I noted above that in Ohio, Kerry led in the best interview-only estimate by 6.5 points with a “standard error” of 3.9 points. A 95% confidence interval for the margin is about double the size of the standard error: plus or minus 7.8 points. So Kerry’s lead was less than the margin of error, and Ohio was too close to call based on the interview data (even if the pollsters accepted nominal 95% confidence, which they don’t). However, since Bush officially won Ohio by 2.1 points, the exit poll discrepancy in Ohio (based on this estimate) was 8.6 points. That discrepancy is beyond the margin of error, at least at a 95% confidence level. As I mentioned earlier, it turns out that at
Yes: overall, and in many states, the exit poll results differed from the official results by beyond the margin of error, overstating Kerry’s performance. (This overstatement is often called red shift, meaning that the “red candidate” Bush did better in the official returns than in the exit polls.) For instance, I noted above that in Ohio, Kerry led in the best interview-only estimate by 6.5 points with a “standard error” of 3.9 points. A 95% confidence interval for the margin is about double the size of the standard error: plus or minus 7.8 points. So Kerry’s lead was less than the margin of error, and Ohio was too close to call based on the interview data (even if the pollsters accepted nominal 95% confidence, which they don’t). However, since Bush officially won Ohio by 2.1 points, the exit poll discrepancy in Ohio (based on this estimate) was 8.6 points. That discrepancy is beyond the margin of error, at least at a 95% confidence level. As I mentioned earlier, it turns out that at
