Underestimating Learning by Doing
研究发现人们在预测自己掌握新任务的速度时系统性地低估了学习效果，即使获得反馈后依然如此；而预测他人表现时偏差较小，表明过度依赖即时感知的投射偏差是主要原因。
Many economic decisions, such as whether to invest in developing new skills, change professions, or purchase a technology, benefit from accurate estimation of skill acquisition. We examine the accuracy of such predictions by having study participants predict the speed at which they will master unfamiliar tasks. Across three studies involving two types of tasks and two levels of difficulty, we find systematic underestimation of learning, even after receiving feedback. In a fourth study, participants predicting others' performance showed significantly less underestimation, suggesting that projection bias—overreliance on immediate perceptions of effort and difficulty—may drive prediction errors.