I was recently involved in a project where I needed to examine some research literature on learning and memory. In particular, I was investigating the spaced learning effect on memory. Memory research has been central to psychology for as long as psychology has existed as an academic discipline, and the spacing effect (also known as distributed practice) has been studied for well over an hundred years. Studies of the spacing effect have shown that when you space learning over separate learning intervals, long term retention is normally much higher compared with the equivalent amount of training from a single or “massed” session. This effect is robust across different time scales, different kinds of learning, and is even true across different species. Another effect, not quite as well studied, is the testing effect. Repeated testing over time is also beneficial for learning, mainly because testing involves effortful memory retrieval, which is advantageous for the formation of long term memories.
Spaced learning (and testing) is to be recommended for the autodictact, but the purpose of this post is not to espouse the virtues of this method of learning, Instead, my main aim here is to have a moan about the non application of this method in education. Most textbooks make use of the repeated testing technique, by the use of quiz sections at the end of each chapter. But it is still relatively rare to make use of spaced testing, where material from previous chapters is also included in an end of chapter test. In higher education institutions (though I speak mainly from experience of the British system), the typical format for teaching is for students to be taught in a single semester, where each week a new topic is introduced, and the course is assessed by a single essay or exam at the end of the course. This design encourages the cramming technique, beloved of procrastinators, where vast chunks of the course syllabus are memorised in a mammoth session the night (and morning) before an exam. This is a valid strategy for investing the minimum amount of time to reap the maximum reward in marks attained, but is a poor technique to maximise long term retention. Of course, conscientious students can use spaced learning techniques. And by their very nature, some disciplines more than others require a form of spaced learning and recall. For example, higher maths involves recall and use of basic maths, whereas the recall of Shakespearean plays is typically not essential in the study of Dickens.
Though there are an many exceptions, it seems that an important part of the design of educational systems is that of convenience. The business of education, is increasingly, a business. The easiest way of administering courses is by the single semester, single assessment model. It means less marking, and less time spent running a course. This makes it popular with academics, and with most students too. Students can learn the material for a course, get the grade, and then forget about it, knowing they will not be tested again. However, if one were serious about taking the spacing effect seriously, then one might design courses that spanned several years, with testing throughout those years. However, I can’t palm off all the blame onto educationalists and academics taking the easy route. Part of the problem lies in the difficulty in applying cognitive psychology to education. Cognitive psychological research typically has not provided the kind of robust evidence for benefits that allows educationalists to take such principles as spaced learning for fact, and worth the effort to implement. In the instance of spaced learning, a research group led by Hal Pashler have undertaken research that straddles the theoretical and applied research border, and are pushing for adoption for the application of spaced learning in pedagogical contexts. A short summary of their work can be found here, which provides further information and some references.