ABSTRACT
This chapter provides practical guidance on the foundational issues for scientific research on expertise, while realizing that other issues are equally important. One ubiquitous concern in research on expertise is the overreliance on relatively small sample sizes. Concerns over statistical power in small samples have been well documented over several decades of psychological research and have been raised more specifically in research on expertise. The aforementioned concerns regarding power and precision lead directly to another general need for advancing the literature on expertise: Moving forward, the literature on expertise should not rely too heavily on p-values alone, or even other inferential indices such as Bayes Factors, which are often highly related. Direct range restriction happens when subjects are selected directly on the basis of their standing on a measured variable of interest.
