Tag Archives: personality psychology

Last week the special issue on replication at the Journal of Social Psychology arrived to an explosion of debate (read the entire issue here and read original author Simone Schnall's commentary on her experience with the project and Chris Fraley's subsequent examination of ceiling effects). The debate has been happening everywhere--on blogs, on twitter, on Facebook, and in the halls of your psychology department (hopefully).
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Sample Size Matters

On this blog and others, on twitter (@mwkraus), at conferences, and in the halls of the psychology building at the University of Illinois, I have engaged in a wealth of important discussions about improving research methods in social-personality psychology. Many prominent psychologists have offered several helpful suggestions in this regard (here, here, here, and here).

Among the many suggestions for building a better psychological science, perhaps the simplest and most parsimonious way to improve research methods is to increase sample sizes for all study designs: By increasing sample size researchers can detect smaller real effects and can more accurately measure large effects. There are many trade-offs in choosing appropriate research methods, but sample size, at least for a researcher like me who deals in relatively inexpensive data collection tools, is in many ways the most cost effective way to improve one's science. In essence, I can continue to design the studies I have been designing and ask the same research questions I have been asking (i.e., business-as-usual) with the one exception that each study I run has a larger N than it would have if I were not thinking (more) intelligently about statistical power.

How has my lab been fairing with respect to this goal of collecting large samples? See for yourself:

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