The testing effect is a phenomenon that seems to reward retrieval practice with better long-term memory retention over passive study alone. Although the effect has been studied for 20 years, there is no consensus theory for why this difference between passive and active learning is consistently found. There are even fewer studies about how the testing effect applies to, for example, the learning and retention of motor skills. To date, almost all literature on the testing effect investigates more academically oriented contexts, such as learning foreign word pairs or recalling images. A new project is now underway to investigate whether the benefits of retrieval practice over passive study holds in other modalities, such as motor-skill learning. The literature suggests the testing effect might generalize this way. The purpose of this project is to better understand what amount of cognitive support is appropriate when learning tasks in, for example, extended reality, human-robot interaction, and human-in-the-loop applications. With the dawn of Industry 4.0, companies are increasingly using extended reality and human-robot collaboration to minimize errors and improve productivity. The literature suggests that there may in fact be downsides to providing limitless, on-demand information during task performance via reduced retention.