Rounded Input Variables, Exact Test Statistics (RIVETS)

Most statistical software packages report the input values to statistical tests (e.g., means and standard deviations for an unpaired t test) in a rounded form (e.g., to two decimal places), with this rounding having been performed after the test statistic has been calculated. However, in some cases, the input values are rounded before the test statistic is calculated, most likely because of some form of manual intervention by the researcher. We describe a method that enables the probabilistic identification of detecting this rounding, the conditions required for this method to be applicable, the tests where pre-calculation rounding can be detected, and the implications of its detection.