What Is Preregistration For?

A paper in Psychological Science was taking a beating on Twitter last month. https://twitter.com/lakens/status/1004119102485614592 In this post, I'm not going to talk about the paper itself but rather, about how it came to be published and how preregistration - a concept I have long advocated - may be being misused. The paper reports on five studies which all address the same general question. Of these, Study #3 was preregistered and the authors write that it was performed after the other four had been completed. It was also larger than the others. The results of Study #3 closely matched the other studies'. So far, so good. However, according to Daniël Lakens on Twitter (I'm not sure how he knows this), Study #3 was conducted on the instruction of the editors (during peer review): https://twitter.com/lakens/status/1004320676206047232 Now, this is where alarm bells started ringing for me. If Psychological Science asked the authors of ...