The previous expansion of EdTech as a substitute for traditional learning around the world, the recent full-scale substitution due to COVID-19, and potential future shifts to blended approaches suggest that it is imperative to understand input substitutability between in-person and online learning. We explore input substitutability in education by employing a novel randomized controlled trial that varies dosage of computer-assisted learning (CAL) as a substitute for traditional learning through homework. Moving from zero to a low level of CAL, we find positive substitutability of CAL for traditional learning. Moving from a lower to a higher level of CAL, substitutability changes and is either neutral or even negative. The estimates suggest that a blended approach of CAL and traditional learning is optimal. The findings have direct implications for the rapidly expanding use of educational technology worldwide prior to, during, and after the pandemic.

中文翻译：

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计算机辅助学习的边际收益递减

EdTech 之前在世界范围内作为传统学习的替代品的扩展、最近因 COVID-19 导致的全面替代以及未来可能向混合方法的转变表明，了解面对面学习和在线学习之间的输入替代性势在必行. 我们通过采用一种新颖的随机对照试验来探索教育中的输入替代性，该试验改变了计算机辅助学习 (CAL) 的用量，以替代通过家庭作业进行的传统学习。从零到低水平的 CAL，我们发现 CAL 对传统学习的积极替代性。从较低的 CAL 水平到较高的 CAL 水平，可替代性发生变化，并且要么是中性的，要么是负面的。估计表明，CAL 和传统学习的混合方法是最佳的。