You may have come across memes posted on your social media feeds setting out just how much your students remember of what you teach them. According to popular wisdom, they will remember something like 10 per cent of what they are told, 20 per cent of what they read and 90 per cent of what they explain to others.

But these numbers are not accurate; they are based on a misunderstanding of an old idea proposed by US educator Edgar Dale, which has now been debunked. And yet, the memes get one thing right: being able to explain a concept clearly is extremely useful in learning. To explain something, you need to have understood it - this is a theory backed by research that is widely accepted.

Reciprocal teaching was highlighted in John Hattie’s seminal Visible Learning study as a high-impact intervention. And in a meta-analysis published last year, a team of researchers from Simon Fraser University in Canada, headed by educational psychology doctoral student Kiran Bisra, analysed 64 research reports, involving almost 6,000 students, and found better learning outcomes in those who received prompts to self-explain while studying or solving problems. In fact, the effect size of “inducement to self-explain” was similar to other high-impact interventions named in Hattie’s analysis, ranking alongside mastery learning and peer tutoring.

But what is self-explanation? The paper describes it as “a process by which learners generate inferences about causal connections or conceptual relationships”.

According to Bisra, that means deep engagement with the topic at hand. “It’s a cognitive activity that learners actively engage with, similar to elaboration or reflection,” she says.

“Explaining concepts or why a particular step must follow another is a powerful cognitive activity; it compels the learner to think about what they already know - their prior knowledge - and integrate it with new information. Or it allows the learner to realise that there is a gap in their understanding and generate inferences to fill it in.”

Not just ‘thinking aloud’

This process is not the same as thinking aloud, Bisra explains, which is simply “a method of collecting verbal data” that reflects what one is thinking about in that moment and offers only a “window into one’s mind”.

Likewise, it is also distinct from summarising and explaining to another person. The paper references a 2000 study from the University of Pittsburgh, and states that “self-explanation is directed toward one’s self for the purpose of making new information personally meaningful. Because it is self-focused, the self-explanation process may be entirely covert or, if a self-explanation is expressed overtly, it may be intelligible only to the learner.”

As natural as this process sounds - of course, we are likely to explain things to ourselves in a way that makes us understand it - Bisra says this is often quite different from what is actually happening in the brains of learners. “I think we’ve all experienced reading something, and then afterwards thinking, ‘What did I just read?’ Or solving a problem by completing a set of steps, but not understanding why one step follows another,” she says.

“In both of those cases, we were passively occupied with the task but not intentionally learning or monitoring our understanding. Self-explanation requires a learner to actively participate in her learning, to make new information personally meaningful.”

It’s a process that more effective learners engage in spontaneously, the paper states, in order to “fill in missing information, monitor understanding and modify fusions of new information with prior knowledge when discrepancies or deficiencies are detected” in something they are studying.

However, prompted self-explanation also has positive effects, Bisra and her team found. The paper references an experiment from a 2013 study, in which two sets of undergraduates (a self-explanation group and a comparison group) were taught about the cardiovascular system from a series of visualisations.

After looking at each visualisation, students in the self-explanation group were prompted with open-ended questions - such as, “can you explain how the blood vessels work?” - and given an empty box to write their answers in. The comparison group were just given the empty boxes and told they could make notes. In a 20-question multiple-choice test afterwards, the self-explanation group performed better.

So, how do you prompt students to self-explain? Posing open-ended questions, as described above, is one method. But, according to the paper, self-explanation prompts can take various forms. One study looked at students learning to play chess with the help of a computer, who were repeatedly asked to predict the next move and explain why they thought the machine would make it. But prompts can be more specific, instructing students to, for example, “write your explanation of the diagram in regard to how excessive water intake and lack of water intake influence the amount of urine in the human body”.

Learners can also be prompted in different directions: to justify or give reasons for a decision or belief; to explain a concept or information in the content; or to explain a prediction. Bisra and her team found that all these approaches could improve performance.

They also found that the benefits of self-explanation remained largely steady against other factors, such as the type of content being studied, the way that students were tested afterwards, and the point at which the self-explanation prompt was introduced in the learning process. This is an important point for schools: it means that self-explanation could be successfully applied across subjects and in different contexts.

Time to reflect

But how can teachers make use of this information in their classrooms? Bisra suggests that it can be as simple as taking a moment to pause and ask students to reflect.

“I can imagine a scenario in which a teacher stops intermittently throughout a lecture and asks her students to write down an explanation for themselves about what is being taught,” she says.

“Sort of a ‘how would you explain this to your future self?’ Or the teacher could embed self-explanation prompts throughout a worksheet - ‘explain why you chose this step to yourself’, for example.

“I also think teachers can role model self-explanation in front of their students. If a teacher is working through a problem, she could stop and give herself a self-explanation prompt. ‘OK, why did I do this step? Perhaps it’s because…’”

In terms of the format of the prompt, Bisra and her team found some evidence that multiple-choice prompts were less effective, probably because students were choosing from a list of possible explanations rather than engaging with the process of creating an explanation of their own.

Returning to an explanation, on the other hand, was found to be extremely effective, with the paper stating that “the most powerful application of self-explanation may arise after learners have made an initial explanation and then are prompted to revise it when new information highlights gaps or errors”.

But Bisra says more research would be useful around whether students should speak or write their self-explanations.

“Most of the studies we reviewed asked students to write down their self-explanation,” she says. “But I’m not sure this is a topic that has been studied thoroughly.

“Often, in research, we take traces of cognitive activity so we can get a sense of whether a participant followed instructions. But I wonder whether a written self-explanation is more effective than a student simply explaining to oneself internally. However, without a trace, we cannot be sure of what a student is doing internally.”

Bisra notes that the vast majority of the studies in the meta-analysis were conducted on undergraduate students, although other ages were also covered and there is “a lot of work still to be done regarding how younger children and teenagers can benefit from utilising self-explanations”.

However, she also points out that these methods are closely linked to a set of learning skills that many school teachers will already be familiar with: metacognitive skills.

“Self-explanation, like many other cognitive activities, is really about metacognition; thinking about thinking,” she says. “The more we can talk to students about becoming aware of their own abilities to control their learning, the more empowered they will be to meaningfully engage in these types of cognitive tactics.”

Zofia Niemtus is deputy commissioning editor (maternity cover) for Tes

This article originally appeared in the 19 April 2019 issue under the headline “Tes focus on...Self-explanation”