Remember this post from three months ago? Now, we have an update by Kenneth Chang in the NYTimes. Prof. Dalibor Sames, the Columbia University professor of chemistry, who retracted two papers in March has now retracted four more papers. These papers were published in 2002 and 2003, and Sames was the lead author in all of them. Reason?
The retractions came after the experimental findings of the papers could not be reproduced by other researchers in the same laboratory.
The professor, Dalibor Sames, was the senior author of all the papers in question. Another author, Bengu Sezen, a former graduate student of Dr. Sames who received her doctorate last year, performed most of the experiments described in the papers.
Bengu Sezen, on the other hand, “has vigorously disputed the retractions. She said she had not been told that the papers were being withdrawn, and she questioned whether other members of Dr. Sames’s group had even tried to repeat the experiments.”
Janet Stemwedel, aka Dr. Free-Ride, has some more thoughts and an analysis of this episode. After examining the available evidence (all of which is from NYTimes, and through its reporter, Kenneth Chang, she has this to say:
Sames says others in his laboratory haven’t been able to reproduce Sezen’s experiments. Sezen says others in Sames’ lab already have reproduced them — and she’s willing to come back and perform the experiments herself under Sames’ supervision. No word on whether folks in other laboratories have tried to reproduce these experiments yet.
Sezen’s consternation here is understandable. The retraction of these papers seems to cast aspersions on her experimental competence, or on her integrity. But if it’s true that Sames didn’t contact her about the problems, that’s fishy.
Given the importance of reproducibility to the scientific enterprise, maybe we need to start thinking about what sort of burden of proof needs to be met before new findings are reported — and what kind of burden of proof needs to be met before we declare findings irreproducible.