“The prevalence of statistical reporting errors in psychology (1985-2013)” accepted for publication at Behavior Research Methods

September 2015

In this manuscript we use the R package statcheck (by Sacha Epskamp & me) to examine the prevalence of statistical reporting errors in 8 major psychology journals from 1985 to 2013. We find that half of all articles contains at least one inconsistency and 1 in 8 articles contains a grossly inconsistent p-value that could have changed the statistical conclusion. We find no evidence that the prevalence of inconsistencies is increasing over the years.

You can find the post-print here: PDF

The Replication Paradox is now published!

June 2015

My latest paper “The replication paradox:  Combining studies can decrease accuracy of effect size estimates” is now published in Review of General Psychology. You can find a postprint of the paper here. The full reference is:

Nuijten, M. B., Van Assen, M. A. L. M., Veldkamp, C. L. S., & Wicherts, J. M. (2015).The replication paradox: Combining studies can decrease accuracy of effect size estimates. Review of General Psychology, 19(2), 172-182. http://dx.doi.org/10.1037/gpr0000034

The R package statcheck is now on CRAN!

November 2014

Statcheck is an R package that Sacha Epskamp and I wrote together. Statcheck extracts statistics and recomputes p-values. Extremely handy to check your own papers for accidental slip-ups in the result section, but it can also be used to estimate error prevalence across a wide range of scientific articles. So far, statcheck can only read results that are reported exactly in APA style. Note that in order to scan PDF files, you need to have the program pdf-to-txt installed and on your path variable. Furthermore, if you want to run statcheck on a Mac, you need to install XQuartz. For more info, see the project page.


Join our seminar “Improving Scientific Practice: Dealing with the Human Factors”, September 11, 2014, Amsterdam.

September 2014

This seminar will take a positive approach and will focus on practical solutions to dealing with human factors in the scientific enterprise. Highly recognized scientists from various research areas who are known for their active involvement in and contributions to the improvement of scientific practice will share their expertise and offer feasible ways to advance the way we do science.

Keynote addresses: John Ioannidis and Melissa Anderson

For more information and registration: www. human-factors-in-science.com