No matter how much time a person spends learning some new piece of information or skill, it will not matter in the long run if that new knowledge is not retained. You cannot apply what you do not remember, and information you cannot apply is of no use to you or anyone else. One of the key factors in ensuring the effectiveness of any eLearning course, is to make sure that it has a methodology in place for ensuring retention.
Retention is just another way of saying that the information is stored in the learner’s long-term memory rather than their short-term memory. Short-term memory is a product of a portion of the brain called the prefrontal lobe, which allows us to hold onto a piece of information for a few moments in order to accomplish some task. Perhaps you need to do a mental math problem, or remember what the beginning of this sentence said so that you can understand the end. In both instances you are using your short-term memory, and after about 15 to 30 seconds the specific fact will fade.
In contrast, long-term memories can be held in the brain from hours to years to even a lifetime. Long term memories are created by passing the short term memory signals from the prefrontal lobe through the hippocampus to be stored throughout the architecture of the brain. The more times the electrical signals are run through the hippocampus the stronger the pathways that are created, and the longer the memory will last. This process is the reason that memories which are recalled frequently last longer, while those that are not recalled often fade with time. Memories function on the general principle of “use it or lose it.”
Between strictly short-term and long-term memory there is a vast gray area. Commonly referred to as working memory, this is the type of memory which extends past short-term, but does not have the same relative permanence as long-term memory. One example of working memory is re-uping information in short term memory every 15-30 seconds to keep it active, but without actually encoding it into long-term memory. Another example is memory associated with a specific task or context, like making a peanut butter and jelly sandwich. There is a classic exercise used to teach people how to code which illustrates this principle nicely. Write down the instructions for how to make a peanut butter and jelly sandwich. If you then take this list of written instructions and hand it to someone who can only follow the instructions exactly to the letter they will almost certainly fail to create an edible or pleasing sandwich.
What this experiment illustrates is that there are some activities (like making a sandwich or riding a bike) which we may think we remember how to do perfectly, but which we actually only really know how to do in the moment. Of course these examples are not strict uses of working memory, but rather an example of where long-term and working memory overlap to produce the required behavior. A lot of what is commonly referred to as “muscle memory” falls into this category of overlap, where the patterns are retained in the long-term memory, but can only be fully accessed within working memory.
From an eLearning context these three types of memory are crucially important. The aim of the course will always be to lock specific bits of knowledge (whether they be facts, skills, or behaviors) into the long-term memory of the person taking the course. This process will necessitate the information to exist first in short-term memory, and to be incorporated into working memory when it is being tested and applied throughout the course. The goal is to make sure the crucial information makes the transition from short-term, through working, to long-term memory, rather than reverting to short-term from working and being forgotten.
This is why intelligent interactions need to be placed throughout the course with a consistent frequency. Interactions help the user move the information they are learning from short-term memory into working memory by applying it to some activity. With enough repetitions the information will move from working memory to long-term memory where it can be recalled over an extended period.
The exact number of repetitions needed to solidify a piece of information in any given individual’s long-term memory will of course vary from person to person, but the richer the stimuli, provided by the information, the fewer repetitions it will take. So the best way to ensure that a piece of information is retained in the long-term memory is to use rich stimuli, incorporate the information into the working memory by applying it, and using spaced repetition, to review and prevent the information from reverting to short-term memory and being lost.