Editing Spacing effect (section)

===Application in education===
Studies have shown that long-term spacing effects are prevalent in learning and produce significant learning gains, particularly when the spacing gaps are on the order of days or weeks.<ref>{{Cite book|title=Learning and Memory: A Comprehensive Reference|last=Byrne|first=John|publisher=Academic Press|year=2017|isbn=9780128051597|location=Boston, MA|pages=481}}</ref> Although it is accepted that spacing is beneficial in learning a subject well and previous units should be revisited and practiced, textbooks are written in discrete chapters that do not support these findings. Rohrer conducted a two-part study in 2006 where students were taught how to solve math problems.<ref>{{Cite journal|last1=Rohrer|first1=Doug|last2=Taylor|first2=Kelli|date=April 19, 2007|title=The shuffling of mathematics problems improves learning|url=https://www.researchgate.net/publication/227181272|journal= Instructional Science|doi=10.1007/s11251-007-9015-8|access-date=April 23, 2016|volume=35|issue=6|pages=481–498|s2cid=55686289}}</ref> In part 1, students either used mass or spaced practice, and spaced practice showed significant improvement over mass practice when tested one week later. In the second part of the experiment, practice problems were either grouped by type or mixed randomly. The desirable difficulties encountered by the randomly mixed problems were effective, and the performance by students who solved the randomly mixed problems was vastly superior to the students who solved the problems grouped by type. The reasoning behind this increased performance was that students know the formula for solving equations, but do not always know when to apply the formula. By shuffling problems around and dispersing them across multiple chapters, students also learn to identify when it is appropriate to use which formula. There is conclusive evidence that cumulative final exams promote long-term retention by forcing spaced learning to occur.