Data fabrication: Can people generate random digits?

Many people have difficulty in generating random numbers. This difficulty suggests that potentially fabricated numbers encountered in investigations of scientific misconduct be examined for nonrandom behavior. The present paper shows that even with a conscious effort to construct random digits, many subjects are unable to produce digits with a uniform distribution. For this study, subjects were directed to try to produce random digits in three places in order to fabricate a series of “pick 3”; lottery numbers. Subjects were most successful at producing a random (uniform) distribution of digits for the leftmost place; however, success at one place was not associated with success at another. In addition, subjects did not select all digits with equal frequency. Of 8,280 digits chosen in this study, the order from most to least chosen was 1, 2, 3, 6, 4, 9, 7, 0, 8, 5. Finally, no strong correlations among subjects’ digit choices were found. The conscious effort by these subjects to produce random digits stands in contrast with the usual case of data fabrication in which the fabricator must devote a conscious effort to choose leftmost digits so the number has the magnitude desired and pays little or no attention to the fact that the rightmost digits should be random. The results of the present paper indicate that even if a data‐fabricator were aware that error digits would be examined for uniformity, success in constructing uniform error distributions is not guaranteed. The difficulty that people have in creating random error digits supports the utility of examining such digits in investigations of scientific misconduct.

Keywords:

• scientific misconduct
• scientific fraud
• data fabrication
• random digits
• uniform distribution
• multinomial distribution
• Dirichlet distribution
• Dirichlet‐multinomial distribution