Adding game elements to higher education is an increasingly common practice. As a result, many recent empirical studies focus on studying the effectiveness of gamified or game-based educational experiences. The findings of these studies are very diverse, showing both positive and negative effects, and thus calling for comparative meta-studies. In this paper we review and analyze different studies, aiming to summarise and evaluate controlled experiments conducted within different scientific disciplines. We focus on the clarity of non-experimental conditions' descriptions and show that in most cases a. educational methods used in control groups' activities are poorly described, b. educational materials used in control groups' activities are often unclear, and c. the starting conditions are unclear. We also noticed that studies in the fields of computer science and engineering, in general, report results more clearly than in other fields. Based on the above finding, we conclude with a few recommendations for the execution of future empirical studies of games in education for the sake of allowing a more structured comparison.

翻译：在高等教育中融入游戏元素已成为日益普遍的做法。因此，许多近期实证研究聚焦于探究游戏化或基于游戏的教育体验的有效性。这些研究的结果差异显著，既呈现积极效应也显示消极影响，从而需要进行比较性元研究。本文通过综述与分析不同研究，旨在总结和评估各科学学科领域内开展的对照实验。我们重点关注非实验条件描述的清晰度，发现多数情况下存在以下问题：a. 对照组活动中采用的教育方法描述不足；b. 对照组活动中使用的教育材料通常不明确；c. 初始条件界定模糊。同时我们注意到，计算机科学与工程领域的研究总体上比其他领域更清晰地报告结果。基于上述发现，我们最终为未来教育游戏实证研究提出若干实施建议，以期实现更具结构化的比较分析。