Nearly 100 scientists spent 2 months on Google Docs to redefine the p-value. Here’s what they came up with

Psychologist Daniël Lakens of Eindhoven University of Technology in the Netherlands is known for speaking his mind, and after he read an article titled “Redefine Statistical Significance” on 22 July 2017, Lakens didn’t pull any punches: “Very disappointed such a large group of smart people would give such horribly bad advice,” he tweeted.

In the paper, posted on the preprint server PsyArXiv, 70 prominent scientists argued in favor of lowering a widely used threshold for statistical significance in experimental studies: The so-called p-value should be below 0.005 instead of the accepted 0.05, as a way to reduce the rate of false positive findings and improve the reproducibility of science. Lakens, 37, thought it was a disastrous idea. A lower α, or significance level, would require much bigger sample sizes, making many studies impossible. Besides. he says, “Why prescribe a single p-value, when science is so diverse?”

Lakens and others will soon publish their own paper to propose an alternative; it was accepted on Monday by Nature Human Behaviour, which published the original paper proposing a lower threshold in September 2017. The content won’t come as a big surprise—a preprint has been up on PsyArXiv for 4 months—but the paper is unique for the way it came about: from 100 scientists around the world, from big names to Ph.D. students, and even a few nonacademics writing and editing in a Google document for 2 months.

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