To understand these numbers, we need to define what some of these numbers mean. First of all, what is “margin of error?” Many people think this means if we say Candidate A leads 49% to 45% with a 3% margin of error, then Candidate A leads by 1-7% (4% +/- 3%)?
In the case of a poll like this where there are only two options, this means 3% is owned by both parties. So 49-45 might mean 46-48 or 52-42. That’s a big gap. However, this is not what margin of error means.
How many of you are tired of reading about polls? Presidential poll, Senate poll, debate poll, local question poll. But since all the numbers you hear about the polls are about math and statistics, many of the same types of numbers used in gaming, I thought I could provide a quick lesson on interpreting some of what you hear visiting lapak303.
The idea for this week’s column came when a friend of mine commented on two recent polls. One shows Candidate A leading by 11 points and the other by 4 points. Both have a 3% margin of error. He stated that one of the polls was clearly wrong.
Missing from the equation is another very, very important number called the “confidence interval.” From what I have read, most political opinion polls use a 95% confidence interval. But, unless they specifically say that, we can’t even be sure of this. So, what is a confidence interval? This means that if the poll is repeated, how likely are we to get a result in the margin of error?
So, if we go back to a poll that says 49-45% with a 3% margin of error, this means if we do another poll we have a 95% chance of ending the poll between 52-42 and 46-48%.
So, that still leaves us with a pretty big gap and quite frankly, “only” a 95% chance of fitting within this range. The other 5% of the time, it might go out of reach. How far? We don’t really know for sure. Is it possible 80-20%? Probably not. There is mathematics that gives us an idea of the range, but these numbers are not told to the general public. But, come back to a post from a friend a friend.