S. Stanley Young, PhD Assistant Director for Bioinformatics National Institute of Statistical Sciences Research Triangle Park, NC
Much is made by some of the experimental biologists that their art is oh so sophisticated that mere mortals do not have a chance [to successfully replicate]. Bunk. Agriculture replicates all the time. That is why food is so cheap. The world is growing much more on fewer acres now than it did 10 years ago. Materials science is doing remarkable things using mixtures of materials. Take a look at just about any sports equipment. These two areas and many more use statistical methods: design of experiments, randomization, blind reading of results, etc. and these methods replicate, quite well, thank you. Read about Edwards Deming. Experimental biology experiments are typically run by small teams in what is in effect a cottage industry. Herr professor is usually not in the lab. He/she is busy writing grants. A “hands” guy is in the lab. A computer guy does the numbers. No one is checking other workers’ work. It is a cottage industry to produce papers.
There is a famous failure to replicate that appeared in Science. A pair of non-estrogens was reported to have a strong estrogenic effect. Six labs wrote into Science saying the could not replicate the effect. I think the back story is as follows. The hands guy tested a very large number of pairs of chemicals. The most extreme pair looked unusual. Lab boss said, write it up. Every assay has some variability, so they reported extreme variability as real. Failure to replicate in six labs. Science editors says, what gives. Lab boss goes to hands guy and says run the pair again. No effect. Lab boss accuses hands guy of data fabrication. They did not replicate their own finding before rushing to publish. I asked the lab for the full data set, but they refused to provide the data. The EPA is still chasing this will of the wisp, environmental estrogens. False positive results with compelling stories can live a very long time. See [i].
Begley and Ellis visited labs. They saw how the work was done. There are instances where something was tried over and over and when it worked “as expected”, it was a rap. Write the paper and move on. I listened to a young researcher say that she tried for 6 months to replicate results of a paper. Informal conversations with scientists support very poor replication.
One can say that the jury is out as there have been few serious attempts to systematically replicate. There is now starting systematic replication. I say less than 50% of experimental biology claims will replicate.
[i]Hormone Hysterics. Tulane University researchers published a 1996 study claiming that combinations of manmade chemicals (pesticides and PCBs) disrupted normal hormonal processes, causing everything from cancer to infertility to attention deficit disorder.
Media, regulators and environmentalists hailed the study as “astonishing.” Indeed it was as it turned out to be fraud, according to an October 2001 report by federal investigators. Though the study was retracted from publication, the law it spawned wasn’t and continues to be enforced by the EPA. Read more…