Methods. We perform a close replication of an experiment investigating the impact (in terms of time and quality) of
design patterns (Decorator and Abstract Factory) on software maintenance. The experiment was replicated once previously, with divergent results. We execute our replication at four universities spanning two continents and three countries using a new method for performing distributed replications based on closely coordinated, small-scale instances (“joint replication”). We perform two analyses: 1) a posthoc analysis of moderators, based on frequentist and Bayesian statistics; 2) an a priori analysis of the original hypotheses, based on
frequentist statistics. R