Dirk Smeesters, professor Consumer Behaviour at the Erasmus University of Rotterdam, is suspected of scientific fraud. Worse than that, he is not the first one. And what really irks me about the issue is the complacency among many researchers, especially natural scientists. Many of them argue that these cases only prove the self-cleansing power of science: after all, hasn't the impostor been caught? Fraud will always be detected.
But how many impostors do not get caught? I think it is more difficult to detect fraud in the social sciences than it is in many (but not all) natural sciences. Take Hwang Woo-Suk, the Korean guy who faked data claiming he cloned human embryos. Such fraud is bound to be detected. His peers will have good reasons to reproduce his results so they can apply the same technique, or even improve on it. Companies may want to commercialize the technique. When it turns out it doesn't work, people would ask him for more details on how he did it, and try again. Somewhere down the line they would get suspicious because he is either not willing to share the details of his work, or his recommendations don't help.
The work of Diederik Stapel and Dirk Smeesters is different. There is less incentive for replication, because the experiments tend to be fairly simple: it is not that they are some fancy new technology. You would not learn anything new from it, and you would not be able to publish it ("We did the same as Stapel et al. but it didn't work" - "Well, your experimental set-up was probably wrong"). Diederik Stapel's findings have been applied in many Dutch schools. The only way to find out whether they worked would have been to do randomly select the schools where we apply the insights - try explaining to parents why their kids are not being taught according to the latest insights in educational science. And even then, our evidence would be no more than a p-value: a probability that the treatment has no effect. Graham Bell could demonstrate his telephone worked, but it doesn't work like that in the social sciences.