A peculiar prevalence of p values just below .05

作者：Masicampo E J^*; Lalande Daniel R

来源：Quarterly Journal of Experimental Psychology, 2012, 65(11): 2271-2279.

DOI：10.1080/17470218.2012.711335

• Statistics
• Statistical inference
• Hypothesis testing

In null hypothesis significance testing (NHST), p values are judged relative to an arbitrary threshold for significance (.05). The present work examined whether that standard influences the distribution of p values reported in the psychology literature. We examined a large subset of papers from three highly regarded journals. Distributions of p were found to be similar across the different journals. Moreover, p values were much more common immediately below .05 than would be expected based on the number of p values occurring in other ranges. This prevalence of p values just below the arbitrary criterion for significance was observed in all three journals. We discuss potential sources of this pattern, including publication bias and researcher degrees of freedom.

• 出版日期2012