Classroom practice - Master the mysterious art of explanation

How can you tell if students have grasped a concept? Ask them to show knowledge of `deep structures' and all will become clear

Greg Ashman

Explanation is at the heart of what we teachers do - look up the definition of "to teach" on any search engine or in any dictionary and "explain" will be at the forefront of every listing.

Yet good explanations are difficult to craft. It is a skill that must be learned and requires constant refinement. So why aren't teachers getting more assistance in doing just that?

Researchers do not seem to be addressing the issue, as an article in Educational Psychologist by Professors Alexander Renkl and Jrg Wittwer notes. "Particularly in educational research, the nature of what makes a good explanation has been largely neglected," they write.

Neither is a focus on explanation apparent at the chalkface. Observations cover many aspects of a lesson, such as the activity type, the assessment strategies and the learning objective. However, they rarely focus on the explanations that teachers give. Why this neglect?

Well, it is particularly hard for schools to evaluate the quality of teachers' explanations given that staff are often observed by a more senior colleague who is not necessarily a subject specialist.

If I go in to a Japanese lesson, a language that I do not know, I can still assess many aspects of teaching, such as whether students are behaving appropriately and completing the tasks that have been set. But I cannot judge the quality of the explanations because I do not even know if what is being said is factually correct.

Does this mean that the solution is for subject specialists to observe lessons? Well, this is also problematic. If I observe a lesson in my own specialist areas - physics and mathematics - then I am not going to experience the explanations in the same way as the students. I already understand the content and so even pretty weak explanations will tend to make sense to me. The best I can do is compare them to those I have crafted myself over the years. Yet the person I am observing may have different ones. Not better or worse, just different. How, then, can I judge if the explanation is actually any good?

By now, you're probably screaming "ask the students if they understand it!". Unfortunately, this is also unreliable. As Professor Daniel Willingham of the University of Virginia in the US writes in his book Why Don't Students Like School?: "There are multiple cues by which each of us assess what we know and don't know. But these cues are fallible, which explains why students sometimes think that they know material better than their classroom performance indicates."

This is where the research should step in - yet as I mentioned, the topic of explanations has been oddly neglected by researchers, perhaps because the prevailing view of how teachers should teach is constructivist rather than teacher-directed.

As a 2006 paper by the late Australian academic Ken Rowe says, in a constructivist philosophy "the role of the teacher is to be a facilitator of learning (rather than a director or orchestrator), and to provide opportunities for individual learners to acquire knowledge through their own activities, and through discussion, reflection and the sharing of ideas with other learners with minimal corrective intervention".

Clearly, such a philosophy does not emphasise the role of teacher explanations. But is it a philosophy shared by teachers? Perhaps. Gregory Yates of the University of South Australia conducted an interesting experiment in 2004. He asked 100 teacher education students the question "What are the traits of highly effective teachers?" Not one mentioned the "ability to articulate clearly".

So how can you improve your explanations when no one seems willing to help? Simply asking students whether an explanation is any good is not the best way to form a judgement, but you can ask a question where the right answer depends on a student applying his or her knowledge correctly. If they have that knowledge, your explanation has worked.

We also know that experts tend to have a much better grasp of the deep structure of problems and concepts than novices. For instance, academics writing in 1981 for Cognitive Science found that physics experts grouped physics problems according to their deep structure - the physical laws that applied to the problem - whereas novices put them together according to surface features such as whether an object sat on a slope or not.

Therefore, if we wish to create real knowledge, an effective explanation should point to the deep structure behind a given situation. This will help students to separate the deep structure from the surface features of each particular example and ensure that the explanation is as comprehensive as possible.

Ultimately, it may be that the key to improving explanations is for teachers to overcome their own humility. The tendency in teaching is to concentrate on the students as all-important at the expense of focusing on their educators. But if this neglects the art of explanation, it may be doing more harm than good.

Greg Ashman is a teacher at Ballarat Clarendon College in Victoria, Australia


Chi, M, Feltovich, P, and Glaser, R (1981) "Categorization and representation of physics problems by experts and novices", Cognitive Science, 5: 121-52.

Rowe, K (2006) "Effective teaching practices for students with and without learning difficulties: constructivism as a legitimate theory of learning AND of teaching?", background paper to address presented at the NSW DET Office of Schools Portfolio Forum, Sydney.

Wittwer, J and Renkl, A (2008) "Why instructional explanations often do not work: a framework for understanding the effectiveness of instructional explanations", Educational Psychologist, 431: 49-64.

Yates, G (2005) "`How obvious': personal reflections on the database of educational psychology and effective teaching research", Educational Psychology, 256: 681-700.

What else?

Making the intangible, tangible: find out how to help your class grasp abstract concepts.

A teacher on the TES Connect forums seeks advice on giving clear explanations.

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