A metastudy is a set of many tiny studies (microstudies) created from a much larger collection of possibilities. Metastudies can yield many of the benefits of time-consuming replications and meta-analyses but more efficiently and with greater attention to generalizability and the causal effects of moderators. Statistical precision and power are higher than in studies with the same total sample size but with fewer conditions and more participants per condition. In this article, we describe metastudies and their benefits, demonstrate how to conduct a metastudy using the well-known risky-choice framing effect as an example, and report on the generalizability of that effect. In three metastudies (total N = 2,338), the framing effect generalized well across most of the potential moderators tested, as was expected. Surprisingly, however, the effect was up to twice as large when the certain option was replaced with a slightly risky option; prospect theory predicts the opposite, and fuzzy-trace theory predicts no difference. Metastudies provide a relatively quick and not-so-painful way of examining an effect's generalizability without waiting for a meta-analysis. Both individual labs and multilab networks are encouraged to shift from traditional studies to metastudies.
Keywords: fuzzy-trace theory; generalizability; heterogeneity; meta-analysis; power; prospect theory; replicability.