After the McCain camp sent me an item touting the fact that their man had gained four points in USA Today/Gallup poll Sunday, gained six points in CBS News/NYT poll yesterday, and was up two (and close to second place) in the ABC/Washington Post poll today, I asked Frank Newport of the Gallup polling organization when we should pay attention to a shift in the polls. Specifically, how many points does a candidate have to increase from the previous poll before we conclude, ‘hey, there’s some significant support building here’?

“Technically speaking, for our Gallup polls, our sample for Republicans is under 500, so our margin of error is 5 points,” Newport said. “In our poll, McCain moved four points, so technically speaking, it is not statistically significant. There may be some indication there, but typically, we want to wait to see if the numbers are continued in subsequent polls. For example, we saw a jump in Romney’s numbers right after the Iowa straw poll, but he’s back down in the latest one, so it was either short-lived, or not statistically significant.”

“Now, I will credit the McCain camp, in that they’ve got three polls showing similar movement,” Newport said. “They have a point, in that if you have multiple independent polls, each of which is moving in the same direction, it does give you a little more faith that you’re tracking a shift or change accurately. There’s no statistical formula for that, but when you have three or four each of them showing the same thing, you have a little more confidence.”

Newport says he’s “a little reluctant to pay too much attention to too much short-term turbulence in these polls… I like to see if trends continue.”

I asked Newport about an argument I heard from a Fredhead, that while some people know Fred Thompson’s face, and some people know his name, not everyone has put the two together.

“One limitation of a telephone poll is that you can’t show someone a picture and say, ‘do you recognize this man,’” Newport said. “On Thompson’s name ID, we’ve seen a significant uptick since April. We’ve asked about ‘Former Tennessee senator Fred Thompson’ and when we first asked in April, 65 percent of all Americans said they didn’t know enough about him to have an opinion. Now it’s down to 45 percent, so he’s gained 20 points in name ID. Now more than half Americans know enough about him to have an opinion; when we started polling on him, it was just a third of Americans.”