Authors of research papers in the medical literature seldom explain how they have determined the sample size to ensure their studies have the necessary statistical power, complains an epidemiologist in a letter to BMJ. 

Professor Jonathan Mayer of the University of Washington in Seattle says that readers are expected to suspend disbelief and assume that the authors have done the calculations correctly, and in the only way feasible. "The assumption can be dangerous, and while suspension of disbelief is a wonderful tool for reading novels, it is completely inappropriate in science" he concludes. "We need to do better." (Source: BMJ 2009;338, p1406)