istician purest, here’s the correct interpretation of the example I’ve been using: If we conducted the identical survey using 20 different samples drawn from the same population, we’d expect the results from 19 of the 20 (95%) to fall within the accuracy interval (+/-5%).
So when we see the pollsters get an election prediction wrong, the reason could be that it was that one out of the 20.
Finally, I promised to define margin of error, sometimes abbreviated as MOE. It’s the same as statistical accuracy.
Survey Design and Data Analysis Workshops
For a more detailed discussion about this topic and all things related to a survey project…