Fanelli D. How Many Scientists Fabricate and Falsify Research? A Systematic Review and Meta-Analysis of Survey Data. PLoS ONE. 2009; 4(5): e5738.
The frequency with which scientists fabricate and falsify data, or commit other forms of scientific misconduct is a matter of controversy. This systematic review considered several surveys asking scientists about misconduct; the differences in their results are largely due to differences in methods. Only by controlling for these latter can the effects of country, discipline, and other demographic characteristics be studied in detail. Conclusions point out that there are many sociological factors associated with scientific misconductthere surveys should adopt standard methodologies to be usefully compared. According to the Author, it is likely that, if on average 2% of scientists admit to have falsified research at least once and up to 34% admit other questionable research practices, the actual frequencies of misconduct could be higher than this.