Thursday, July 12, 2012
but replications are possible
I can't go into any detail (yet), but this image is a few slices showing the results with the first dataset in red and the second in blue. We definitely tweaked the analysis of the first dataset a bit; I did as much of the tweaking as possible with a control classification rather than the real one, but I can't claim that all the choices were made on a priori principle. But I would claim that the choices were made without any data peeking for the second dataset: the blue blobs are the very first set of across-subjects results; just the analysis we used for the first dataset. And I'm extra-pleased by these results because they are properly independent: different scanner, different people, even different stimuli (but the same task and experimental questions, of course).
Within the last week I've actually had another case of replicating results in properly independent datasets; a completely different set of analyses than the blobs above. It's an anatomical ROI-based analysis, so I don't have pretty pictures to show, but the tables are very lovely.
So do not give up hope: replications are possible. But we must be very vigilant in our methods: we are all easy to fool.