Who's winning in the polls? What do the polls mean?
What should you consider in evaluating for yourself what these polls mean?
This is the last of a six-part series in which we looked at poll variables to help you sort through the garbage to find the gold nuggets in the polling world.
Here are the top 5 tips:
1. Who? Be sure to look at who participated in the poll. Is it a random poll or a self-selected sample?
2. When? Is the poll more than 3 days old and have any intervening events occurred since the poll was conducted that might change the result? i.e. financial crash.
3. How? Are the questions as worded biased, leading, or complex? Do they use double-negatives?
4. Race matters? Does race matter? Be aware of the possible Bradley Effect, or higher poll numbers for the minority candidate because people won't disclose their racial biases in a poll. Poll numbers do not necessarily reflect how the participants will actually vote once they are alone in the booth.
5. Size and margin of error. As a general rule, samples of 1,000 or more are considered statistically reliable, with a small margin of error of plus or minus 2%. The smaller the sample, the higher the margin of error. The larger the sample, the lower the margin of error. A sample of 50 people, showing a 55% lead to 45% can vary significantly, giving the "leader" a possible range of 40%-70%, and the "loser" a range of 30% to 60%. There's a 30 point overlap, making this kind of a result extremely unreliable, especially in a "close" race. In contrast, a 1,000 sample showing a 55% lead to 45% means that the leader has 53-57% and the other 43-47%. This can be fairly interpreted as a lead.
Bonus Tip: TV call-in polls and Internet polls are inherently unreliable.
By evaluating these few variables, you know more clearly how to interpret poll results for yourself. And you won't be misled by the latest polls trying to tell you who's going to win the election.
And please, don't ever, ever let poll predictions keep you from casting your vote. It's not over until it's over. Vote!!