It will be interesting to see how this is received among psychologists more generally.
Yes, it will. My prediction is that they will take little notice of it. Not of lot of comments one way or the other.
However, even if non-artefactual, these experiments don't seem to have anything to do with what we think of as 'psi'. I realize that psi has now been defined in such a way as to incorporate these results, but it borders on bizarre to claim that the potentially tiny effect of a fuzziness in our perceptions on the order of milliseconds can be presumed to relate to claims of presentiment.
When I was young, I used to hear adults around me talk about those silly scientists. Always telling them that something or other was bad for them. They would describe the scientists as giving a few mice tremendous overdoses of whatever they were testing to see if it would be toxic to humans. How stupid was that!
When I was older and learned more about science, I came to understand why they conducted those experiments that way. It wasn't stupid, it was actually quite well considered.
The way we measure and test things in the laboratory is quite different from what people might experience in the "real world". There are reasons for that. What we can reasonable measure is one of the constraints that experimenters must deal with.
It would make more sense to relate these experiments to those of Libet, I think.
I agree. It might be interesting to concoct a hypothesis about it.
Bem's work is impressive, and this looks to be a more solid demonstration of psi than the ganzfeld. But I do wonder about the lack of a control group.
Actually, there are control groups with the last two experiments. Results are at about the same level of significance. The other experiments had control trials along with the experimental trials, so there was control data for each test subject. This was built into the test statistic.
But if the image is of, say, a person then the choice isn't random. Am I right in thinking that there was a study done that showed that people preferred pictures of people facing to the right? So the initial choice of the subject isn't random. So those occasions where the computer chooses the rightward option, you can't say “Ah, this is retro-causation making people choose this option” because that's what they've more likely to have chosen anyway. And while you'd expect that to even out to 50% of the time, I'd like to be sure that the experimenters knew about this effect and accounted for it. After all, we're looking at a difference of a couple of percentage points on that particular experiment. It'd be interesting to see how the figures were for those targets which otherwise would have been chosen less frequently.
He goes into quite a bit of detail about the randomization procedure. I didn't attempt to read through all of it, but if you are interested, detailed technical information appears to be available. The randomization seems well done to me although I'm not familiar with the actual algorithms he references. In addition, different randomization schemes were used with different experiments. They have gone to a good deal of trouble and thought on that part of the set up.
Where are you reading this, roger?
I agree with you that it's rather odd that all the supposedly time-consuming work was spread over many different kinds of experiments.
~~ Paul
Actually, I would guess that these experiments were done sequentially. They all have a similar set up. The changes seem almost like tweaking to try to more precisely hone in on whatever it is that is showing up as significant in their experiments.
Why did they use one-tailed tests? Wouldn't it be just as interesting if the subjects guessed significantly under the expected number?
Actually, they are explicit about which direction they expect the target hits to move in and why. There are some test situations where they are looking for a negative move rather than a positive one. The one-tailed test is appropriate.
It's also interesting to note that nonerotic but negative images did not produce any results. I guess the subjects realized that it was the erotic images that were important.
~~ Paul
I would guess the experimenter realized that erotic images were more likely to induce a predictable reaction. Incidently, the expected direction is negative for the erotic images. He expected it to produce fewer target hits and it did.
Say, this would be perfect for an online experiment where you could recruit thousands of people. A little Java applet would do the trick.~~ Paul
Yes, that's quite true. It would be interesting to see what the results would be over such a large sample. Do you think it likely he will do so?
