This article reviews educational efforts to promote a responsible conduct of research (RCR) that were reported in scientific publications between 1990 and early 2020. Unlike previous reviews that were exploratory in nature, this review aimed to test eleven hypotheses on effective training strategies. The achievement of different learning outcomes was analyzed independently using moderator analysis and meta-regression, whereby 75 effect sizes from 30 studies were considered. The analysis shows that the achievement of different learning outcomes ought to be investigated separately. The attainment of knowledge strongly benefited from individualized learning, as well as from the discussion and practical application of ethical standards. Contrarily, not covering ethical standards tended to be a feature of successful courses, when looking at other learning outcomes. Overall, experiential learning approaches where learners were emotionally involved in thinking about how to deal with problems were most effective. Primarily intellectual deliberation about ethical problems, often considered the "gold standard" of ethics education, was significantly less effective. Several findings from previous reviews, e.g., the preferability of mono-disciplinary groups, could not be replicated with multivariate analysis. Several avenues for future research efforts are suggested to advance knowledge on the effectiveness of research integrity training.