A primer on assessing intelligence in laboratory studies

This paper is an attempt to provide a brief guide to major conceptual and statistical problems that are unique to the study of individual differences in intelligence and various intellectual abilities, in the context of laboratory experimental studies, and to suggest strategies to successfully navigate these problems. Such studies are generally designed so that the goal is to evaluate the relationships between individual differences in basic task performance or related markers on the one hand, and individual differences in intellectual abilities on the other hand. Issues discussed in this paper include: restriction-of-range in talent, method variance and facet theory; speed vs. power; regression to the mean; extreme-groups designs; difference scores; differences in correlations; significant vs. meaningful correlations; factor- pure tests; and criterion variables. A list of representative “do” and “don’t” recommendations is provided to help guide the design and evaluation of laboratory studies.