Pre-Registered Interim Analysis Designs (PRIADs): Increasing the Cost-Effectiveness of Hypothesis Testing

We show that group sequential designs (which allow to perform interim analyses while data collection is ongoing) can unlock numerous benefits for researchers engaged in confirmatory hypothesis testing: They facilitate sample size decisions, allow researchers to achieve a desired level of statistical power with a smaller number of observations, and help conduct more efficient pilot studies. We validate this cost-saving potential through a comprehensive re-analysis of 212 studies published in the Journal of Consumer Research, which shows that using these designs would have reduced costs by 20% to 29%. We conclude with a discussion of limitations and possible alternatives.