Fearing the Future of Empirical Psychology: Bem's (2011) Evidence of Psi as a Case Study of Deficiencies in Modal Research Practice

In this methodological commentary, we use Bem's (2011) recent article reporting experimental evidence for psi as a case study for discussing important deficiencies in modal research practice in empirical psychology. We focus on (a) overemphasis on conceptual rather than close replication, (b) insufficient attention to verifying the soundness of measurement and experimental procedures, and (c) flawed implementation of null hypothesis significance testing. We argue that these deficiencies contribute to weak method-relevant beliefs that, in conjunction with overly strong theory-relevant beliefs, lead to a systemic and pernicious bias in the interpretation of data that favors a researcher's theory. Ultimately, this interpretation bias increases the risk of drawing incorrect conclusions about human psychology. Our analysis points to concrete recommendations for improving research practice in empirical psychology. We recommend (a) a stronger emphasis on close replication, (b) routinely verifying the integrity of measurement instruments and experimental procedures, and (c) using stronger, more diagnostic forms of null hypothesis testing.