[Rudism]

Originally Posted by Phronk

Well, I thought I made it clear that there was a good reason for throwing them out; they're not relevant to the question being asked.

What exactly is the question being asked? This is from the abstract of the published paper:

Aimée Morgana noticed that her language-using African Grey parrot, N'kisi, often seemed to respond to her thoughts and intentions in a seemingly telepathic manner. We set up a series of trials to test whether this apparent telepathic ability would be expressed in formal tests...

The parrot "often" seems to respond. They want to test if this is true. Seems to me that any trials where the bird doesn't respond is directly relevant to the question being asked. The question has been redefined after the fact because the actual data didn't support the original hypothesis.

Originally Posted by Phronk

Think of it this way. A guy claims he's really good at predicting coin flips, but only when it's sunny outside. He predicts coins in a room with a window and is videotaped. The coin flipper goes on flipping no matter what, but sometimes it gets cloudy outside. Later, the videotape is examined, and trials where it was cloudy out are thrown out, because that wasn't the guy's claim.

There's no real equivalent to the "cloudy out" part of this analogy in the parrot example, but I will grant you that in this case it wouldn't make a difference. Also, the guy making guesses should be allowed to make more than one guess on trials when he feels like it (which, in this case, would always result in a hit, since there's only two possible guesses he can make). In this case, we would expect an overall hit rate of greater that 50%, since the "heads tails" guesses would skew it in that direction. You're claim is that the random permutation analysis would allow us to say whether or not the results are significant even with the "heads tails" guesses factored in. I'm not so sure about this, but I'm curious enough that I'm going to try to get a copy of the actual paper and delve into some math myself to see what they actually did.