We all experienced that nerve-racking moment during an exam when we stared at a question that we were sure we know the answer to. We studied it. We memorized it. We knew the information went in, but we couldn’t seem to pull it back out.

What happened to the information we spent so much time learning? Where did it go? Why couldn’t we retrieve it when we needed to? Often, we chalk this problem up to a lack of focus or understanding, but this reason is incomplete.

Learning and Memory

To understand why retrieval is sometimes so challenging, it is important first to understand the three memory processes. The first is encoding, when our brains process sensory information into a format that it can store. Once information is encoded, it goes through the second process: storage. Storage involves the transfer of information into either short-term memory or long-term memory. Short-term memory has a limited capacity and can hold about seven items for 20 to 30 seconds at a time. In contrast, long-term memory has an unlimited capacity. The way learners encode information determines whether they store it in short-term or long-term memory. The third memory process is recall, which is the retrieval of information that has been encoded and stored.

If learners don’t encode and store information well, it will be hard for them to recall it. Most learning strategies focus on the processes of encoding and storage, but research demonstrates that strategies that focus on the process of recall, or retrieval, are equally vital to learning. When learners find that they’re unable to recall information despite having studied it, it is usually because they haven’t had any practice in retrieving information.

Retrieval Practice: The Testing Effect

Retrieval practice, sometimes called the testing effect, is a strategy in which learners practice bringing stored information “out” of their mind. Practicing recall makes information easy to retrieve even after a significant amount of time has passed.

Often, learning strategies fall short because they involve passive learning: listening to an instructor explain a concept, reading content or watching a video, for example. Memory researchers have found that while passive learning may contribute to short-term learning, it does little for long-term learning. In contrast, retrieval practice is an active process that requires learners to challenge themselves. Think of recall as a muscle: The more someone exercises it, the stronger it becomes.

Many learners believe they have successfully learned something if they test themselves once and are able to retrieve the information successfully. However, this approach does not ensure that their brains have passed information into long-term memory. For retrieval practice to be effective, it should be an ongoing process. Repeated retrieval practice strengthens the neural pathways used to recall information. The more a learner uses a neural pathway, the easier it is for him or her to recall the information.

Methods of Retrieval Practice

Once learners complete a course or finish consuming a piece of content, they should actively try to recall that material using retrieval practice. Strategies include the use of flashcards, short quizzes, self-tests and verbal questioning. Self-tests can be as simple as answering questions at the end of each lesson or performing a “brain dump.” In a brain dump, the learners write down everything they remember about the topic on a piece of paper, review and verify it, and reexamine the concept to commit it to memory.

What the Research Shows

Psychology researchers Jeffrey D. Karpicke and Henry L. Roediger conducted two studies to demonstrate that the process of active recall is effective in improving learning. They gave a group of students 40 Swahili/English word pairs to learn and then tested them. Students in the group who engaged in passive learning only remembered 34% of the words, compared to 80% for the other students.

A second study involved three groups of students. One used active recall methods, one used passive methods like reading and one used elaborative methods like creating mind maps. Results showed that the group that engaged in active recall performed better than the other two groups by a 50% margin.

Retrieval Practice in Online Learning

Retrieval practice is especially vital in a virtual setting. Short modules are ideal for e-learning and should be supplemented with quizzes, knowledge-checks, problems to solve or other forms of assessment. Then, courses can present problems that require learners to integrate the knowledge they gained over a few lessons.

Retrieval practice is most effective when it is an ongoing process. A single problem or quiz on each concept isn’t enough. The training program should space out and repeat active recall activities for each concept to prevent forgetting.

While active recall is a relatively new learning strategy, there is a growing amount of research that supports its effectiveness. Retrieval practice can be challenging, and learners should be prepared to face a fair amount of frustration at the outset. However, as with any skill, retrieval becomes easier with practice, and it has many benefits in the long run.