Consistency errors in p-values reported in Spanish psychology journals.

BACKGROUND

Recent reviews have drawn attention to frequent consistency errors when reporting statistical results.

METHOD

We have reviewed the statistical results reported in 186 articles published in four Spanish psychology journals. Of these articles, 102 contained at least one of the statistics selected for our study: Fisher-F , Student-t and Pearson-c 2 .

RESULTS

Out of the 1,212 complete statistics reviewed, 12.2% presented a consistency error, meaning that the reported p-value did not correspond to the reported value of the statistic and its degrees of freedom. In 2.3% of the cases, the correct calculation would have led to a different conclusion than the reported one. In terms of articles, 48% included at least one consistency error, and 17.6% would have to change at least one conclusion. In meta-analytical terms, with a focus on effect size, consistency errors can be considered substantial in 9.5% of the cases.

CONCLUSION

These results imply a need to improve the quality and precision with which statistical results are reported in Spanish psychology journals.