STATISTICAL SIGNIFICANCE TESTING AND CUMULATIVE KNOWLEDGE IN PSYCHOLOGY - IMPLICATIONS FOR TRAINING OF RESEARCHERS

Data analysis methods in psychology still emphasize statistical signif icance testing, despite numerous articles demonstrating its severe def iciencies. It is now possible to use meta-analysis to show that relian ce on significance testing retards the development of cumulative knowl edge. But reform of teaching and practice will also require that resea rchers learn that the benefits that they believe flow from use of sign ificance testing are illusory. Teachers must revamp their courses to b ring students to understand that (a) reliance on significance testing retards the growth of cumulative research knowledge; (b) benefits wide ly believed to flow from significance testing do not in fact exist; an d (c) significance testing methods must be replaced with point estimat es and confidence intervals in individual studies and with meta-analys es in the integration of multiple studies. This reform is essential to the future progress of cumulative knowledge in psychological research .