Occasionally, you see the claim that agreement attraction is a laboratory phenomenon. See the first bullet point above.

## The Replication Crisis

Andrew Gelman has a very thoughtful reply here to Lisa Feldman Barrett’s op-ed in the NYTimes, in which she claims that the ‘crisis of replication’ in psychology is not really a crisis at all, but rather reflects flourishing science. I agree with essentially all of Gelman’s points. (Thanks to Caren Rotello for pointing me toward Gelman’s blog.)

## Sabbatical Spring 2015

I will be on sabbatical during spring 2015. Starting in December 2014, I may not reply to email quite as rapidly as usual, but I will, eventually, reply. Students who are interested in working in my lab in Fall 2015 should drop me a line at some point in late spring or over the summer.

I’ll be around more than not, though I’ll be doing some work-related travel to talks and conferences. In the summer, I will be in Paris as a Visiting Professor for the Labex EFL Project, where I’ll be giving some lectures about predictability effects in language comprehension. I’ll also be teaching a mini-course at the University of Salzburg on eye movements in reading, and teaching at a summer school at the University of Milan-Bicocca.

## Positive Predictive Value

Welcome to my new website, still very much under development.

To have something to put in a first post, I’ll link to this very interesting Nature Reviews Neuroscience paper by Button et al. (2013); thanks to Neil Berthier for bringing it to my attention. The paper discusses a statistical concept I hadn’t previously encountered, “Positive Predictive Value” (or PPV), which is the conditional probability that given a rejection of the null hypothesis, the null is actually false. It points out that PPV depends very strongly on statistical power: For low powered studies, it can be the case (given some assumptions about the base rate of true vs. false null hypotheses) that most rejections of the null actually arise when the null is true! The paper is primarily concerned with the problem this presents for the interpretation of human neuroscience studies, but it’s clearly a problem for other branches of psychology as well. The moral here is that the power of your study not only influences the probability of rejecting the null, if the null is false; it also influences the probability that a rejection of the null, if you do reject, corresponds to a real effect. This result provides some justification for the intuition that I (and maybe most people) have that results meeting conventional tests for statistical significance (i.e., p < .05) are still to be taken less seriously when the study is very small.