I saw this survey get reported by several sites last week and I’ve spent a number of hours since then thinking about it because I’m a deeply thoughtful person and there was nothing good on TV and also I don’t have cable anymore anyway.

The survey, conducted by the Pew Research Center’s Project for Excellence in Journalism (or SHIELD for short), says the iPad’s share of the tablet market has dropped from an astounding 81 percent a year ago to just 52 percent this year.

Sounds bad for the iPad, right? Once again we see that there is no market share Apple can have that Dr. René Belloq Android cannot take away.

Here’s the thing, though: I don’t buy the results of this survey. And by “don’t buy” I don’t mean “I didn’t purchase the white paper published by the Pew Research Center’s Project for Excellence in Journalism (SHIELD).” I mean I don’t believe the results.

OK, Apple fanboy, lol, and maybe I’m wrong, but this is a survey. I don’t really understand how a survey is more meaningful than published sales numbers. Amazon famously doesn’t release sales figures for the Kindle line, so we’re left to speculate on exact market share, but it’s worth noting that both IHS and Strategy Analytics pegged the iPad’s market share at over 68 percent during the same period that Pew says it was just 52 percent.

I’m no statistician (although I do play in a fantasy statistician league), but I can tell you that all three of these data points cannot be correct at the same time.

Last year Pew conducted the survey before the Kindle Fire was released. This year they conducted it before the Nexus 7 or the Kindle Fire HD were released. Which is part of what I don’t get. While about two-thirds of the shift is attributed to the introduction of the Kindle Fire, the rest has simply no explanation at all. We’re to believe that after consistently turning their noses up at garden variety Android tablets, consumers suddenly started buying them in the last year because… why? Pew says the reason people bought more Android tablets was because prices fell. But prices on tablets not shipped by Amazon and Google didn’t really fall that much. The 7-inch Galaxy Tab 2 is still $350 at Verizon.

(Which is another interesting point here. If you think Google and Amazon are going to stick it to Apple on price, what effect do you think the Kindle Fire HD and the Nexus 7 are going to have on other Android tablets? Devastating, I’d say.)

Yet this survey shows them increasing market share over the last year. For some reason. While I’m willing to accept the idea that the Kindle Fire took a decent chunk of market share, you’re going to need to prove to me that other Android tablets did.

There’s something else a little funky about Pew’s survey. According to the details of the entire study, they only surveyed people 18 years and older. I find it a little odd that they’d make such sweeping generalizations about market share when they left out a rather large segment of the market in their survey.

While I have my doubts about the Pew survey, I truthfully don’t know who’s right. I certainly expect the Nexus 7 and the Kindle Fire HD to be competitive and take at least some market share from Apple this year. But given their restricted demographic and published estimates that contradict their numbers, I see no real reason to take the results of the Pew survey very seriously.

Maybe we also shouldn’t take IHS and Strategy Analytics numbers that seriously, either. Or a whole lot of other surveys and polls for which we know nothing about the rigor with which they were conducted.

These are all just individual data points and any one of them may be indicative of a trend but, as you can see with the varied answers we’ve gotten about iPad market share, we really don’t know which one it is.