Eleanor Miles’s research while affiliated with University of Sussex and other places

While direct replications such as the “Many Labs” project are extremely valuable in testing the reliability of published findings across laboratories, they reflect the common reliance in psychology on single vignettes or stimuli, which limits the scope of the conclusions that can be reached. New experimental tools and statistical techniques make it easier to routinely sample stimuli, and to appropriately treat them as random factors. We encourage researchers to get into the habit of including multiple versions of the content (e.g., stimuli or vignettes) in their designs, to increase confidence in cross-stimulus generalization and to yield more realistic estimates of effect size. We call on editors to be aware of the challenges inherent in such stimulus sampling, to expect and tolerate unexplained variability in observed effect size between stimuli, and to encourage stimulus sampling instead of the deceptively cleaner picture offered by the current reliance on single stimuli.

As part of their Many Labs project Klein et al. (2014) replicated the effects of an imagined contact study carried out by Husnu and Crisp (2010). In their report the authors argue the data provides weak support for replicability. However, the effect observed was both significant and comparable to that obtained from a recent meta-analysis for the relevant outgroup. This suggests that the Many Labs project may provide stronger support for the existence of imagined contact effects than currently thought. We discuss the value in interpreting replications within the context of the existing literature.