Nuijten MB, Hartgerink CHJ, van Assen MALM, et al. The prevalence of statistical reporting errors in psychology (1985-2013). Behavior Research Methods 2015:1-22
This study documents reporting errors in a sample of over 250,000 p-values reported in eight major psychology journals from 1985 until 2013, using the null-hypothesis significance testing (NHST). Results showed that half of all papers contained at least one p-value that was inconsistent with its test statistic and degrees of freedom. One in eight papers contained a grossly inconsistent p-value that may have affected the statistical conclusion. This could indicate a systematic bias in favor of significant results.