Power considerations in bilingualism research: Time to step up our game

Low power in empirical studies can be compared to blurred vision. It makes the signal ambiguous, so that conclusions depend more on interpretation than on observation. Data patterns that look sensible are published as evidence for theoretical positions and unclear patterns are discarded as noise, whereas both could be due to sampling error or could be a perfect reflection of the population parameters. Simulations indicate that little research with sample sizes lower than 100 participants per group provides a picture of enough resolution to draw firm conclusions. This is particularly true for research comparing groups of people and involving interaction effects. As a result, it is to be feared that many findings in bilingualism research do not have a firm base, certainly not if they go beyond a simple comparison of two within-participants conditions.

Automated summary

Low power in empirical studies, like blurred vision, can lead to ambiguous signals and reliance on interpretation rather than observation. This can result in unreliable conclusions and findings with significant errors due to insufficient sample sizes, especially in studies comparing different groups or involving interactive effects.