@roulis:
I think it would be fair to presume that the experiments would have been performed as part of the investigation. The context gives two points - when confronted by a stall in that scenario, 80% of the pilots who took part in the experiment reflexively pulled up. If so, then it was an adjunct to the investigation itself rather than a scientific study in its own right. I'd imagine the pilots were taken from a reasonably broad cross-section of those available.
As far as I'm concerned, quibbling over the parameters of the experiments would have been far less concerning at the time than the significant number of those tested who did indeed pull up! I also think that the lack of surprise at the figure from posters known to be experienced pilots is rather telling.
Going back to a previous reply of yours - the point I was making regarding other incidents in which ex-military captains were responsible for pulling up was simply to highlight that it would be unwise to "write off" the actions of the AF447 PF as being purely down to inexperience.