Understanding the confidence interval will help you grasp what an election poll is -- or is not -- saying. As you might have guessed, the media consistently gets it wrong.

If a margin of error is plus or minus 3 percentage points, the margin of error on the difference between them is about double – or 6 percentage points, in this example.

An Example of Margin of Error and Confidence Levels The key to the validity of any survey is randomness.

Confidence intervals are often misrepresented and are commonly misunderstood, even by researchers.

Confidence intervals for the variance of a normal distribution with unknown mean are constructed which improve upon the usual shortest interval based on the sample variance alone. These intervals have ...

Using this t statistic in the standard error, one can express the expected width of the confidence interval as a function of the sample size. Alternatively, a sample size can be found to achieve a ...

In 2023, Casellina, Landini and Uberti determined MoC C of probability of default estimates based on a confidence interval of the long-run average default rate. Although their approach disregards the ...

The 95% confidence interval means that 95% of the time, those other polls’ responses would be within 3 percentage points of the answers reported in this one poll.