The Teacher’s Job is to Explain— To “Make Plain”
I have made the claim before that a teacher is essentially an “explainer.” I’ve sometimes felt some resistance from others to that claim, and I think I know why. When I state that a teacher is an “explainer,” for some it conjurers up an image of a dry, boring lecture such as the case of the economics teacher (played by Ben Stein) in Ferris Bueller's Day Off (“anyone, anyone…”). This is not my idea of an “explainer,” so let me try to “explain” my claim below.
Etymology of the Word
The modern English word “explain” is derived from the latin ex, meaning “out,” and planus, meaning “to level, flatten, or smooth.” Connected to planus we also get “plains,” as in large expanses of flat landscape, and “to plane wood,” meaning to smooth and level it. In other words, the literal latin components of “explain” mean to “level out” or “flatten out.” The idea of “making something plain” came to figuratively refer to making it clear, understandable, intelligible. A listener may respond to someone speaking with a lot of technical jargon by exclaiming, “tell that to me again in plain language, please.” In other words, to explain something is to make it clear and understandable to another person. It’s to unpack a complex idea or concept and present it plainly — to figuratively unfold it and lay it out flat — for the other person to comprehend it.
Now that we’ve dissected it (I’m mixing too many metaphors), I’d like to discuss several implications of the word “explain” and how it describes the core task of the teacher.
The Teacher Must Know The Topic Conceptually
The first implication is that a teacher, in order to explain a topic, must know that topic at a deep conceptual level. In order to unpack and unfold a topic, to lay it out for another to comprehend (i.e. the student), the teacher must know its component parts, how they fit together, how they’re ordered and layered, which are essential, and which are periphery. This, I believe, is also where a difference arises between someone who knows a topic and someone who can explain it to others. The explainer — the teacher — must also know the prerequisite knowledge assumed within the topic. What are the related foundational concepts? What is the background knowledge that one needs to have as a starting point? I’m sure you’ve had the experience where someone has attempted to explain something to you, but failed because their starting point was miles ahead of your entry point into the topic. I know someone who does foreign currency hedge trading for a living. Despite several attempts by him to explain what he does, I don’t really understand it.
This is partly what makes the job of the teacher a challenging one. Following Piaget, many cognitive psychologists talk about schema development as the way we form knowledge. Schema are often represented as complex, interconnecting webs of information that piece together to form mental concepts. The schema for one concept connects with, builds on, and overlaps with the schema for related concepts. A teacher must know the topic at a deep conceptual level and, metacognitively, be able to reflect on their own schematic knowledge construction of the topic to recognize the taken-for-granted elemental concepts that the student will need to understand first.
The Teacher Must Know How the Student Conceives of the Topic Already
It’s rare that a person comes to a topic with a complete mental blank slate. Most of the time we’ve already encountered something about a topic and thus we’ve already formed certain conceptions. These conceptions may be rudimentary and may be flawed in some ways, but, based on experience up to that point, these conceptions have helped us make sense of our world. Sometimes people talk about preconceptions or misconceptions— whatever the terminology, the point is that we almost always approach a topic with some sort of conceptual framework already in place. For example, I don’t understand what it means to engage in foreign currency hedge trading, but, even before my friend tried to explain it to me, I had some experience with foreign currency, I knew what it meant to trade something, and I’d heard the phrase “to hedge your bets.” I definitely already had a conceptual starting point.
This is a skill that defines a good teacher, and something that’s required for effective explanation— in addition to a deep conceptual knowledge of the topic, the teacher must also know the conceptual starting point of the student. How can the teacher possibly know this? Well some of it comes from the experience of explaining a topic to many different students over time. The teacher gradually comes to know the common conceptual starting points of students related to a particular topic. This knowledge also comes from teachers asking the right questions, or providing the right prompts. In education, we call this formative assessment; it’s the questions the teacher asks of students and the tasks the teacher assigns to students that allow the teacher to gain insight into how the students conceive of the topic and provide guidance to the teacher on how to best proceed with the explanation.
The Teacher Must Have the Tools to Guide the Student to Refine and Develop Their Conceptions
Returning to Piaget again, he referred to cognitive development as a process of equilibration; Piaget argued that equilibration involved two processes. One he called assimilation, which is the process of integrating new information into already existing schema; this expands the already existing schema, meaning that the learner develops a more detailed and nuanced conceptual understanding of the topic. Their knowledge of the topic grows from something simple to something more complex. The other process Piaget called accommodation, which is when new information prompts a change to the already existing schema; in other words, the new information requires the learner to re-conceive of something they thought they previously understood. With the new information, the learn comes to realize that a former conception was inaccurate or misleading in some way; the new information forces a schematic change towards a better conception of the topic.
Piaget, though his ideas about cognitive development have been very influential, tended to speak of cognitive development as if it happened automatically in the learner apart from any social context. Vygotsky, on the other hand, helpfully emphasized that cognitive development happens while the learner is surrounded by more experienced and knowledgeable others (i.e. parents or teachers), who provide support, guidance, and models that help to carry some of the cognitive demand for the new learner as they learn. This idea of cognitive support from a more knowledgeable other during cognitive development is often referred to as scaffolding.
Now we come to the final component of an effective explainer, and this is where I like to point to a bridge-building metaphor. Imagine that the teacher is on one side of a valley. On that side, she already has a degree of expert knowledge on the topic. On the other side of the valley is the student; on that side, the student is a relative novice to the topic. Following a constructivist view of knowledge and learning, the student must build their own bridge to get to the other side— the student must build their own understanding of the topic. The teacher cannot construct the mental schema for the student; that requires intentional, hard mental work by the student. However, the teacher, based on their own deep conceptual understanding of the topic and based on their metacognitive reflection on their own schema development, can provide blueprints, materials, tools, examples, models, opportunities for practice, and feedback— the teacher can provide the scaffolding that will help support the student’s knowledge construction.
To Make Plain
Together, this is what is required for a teacher to explain something to a student. In order to make a topic plain, clear, and comprehensible, so that the student possesses his own mental clarity of the topic, the teacher must a) have a deep conceptual understanding of the topic, including the metacognitive awareness of her own schema development, b) have insight into how the student currently conceives of the topic, and c) be able to implement the materials, tools, models, examples, metaphors, and practice exercises to provide the cognitive scaffolding that will guide the student to their own mental clarity.
The Wisdom of Practice
Lee Shulman, who first coined the term Pedagogical Content Knowledge (PCK), wrote of the “wisdom of practice” as one of the key sources of PCK. In other words, one becomes a better explainer — a better teacher — through the on-going practice of explaining. With each of the components listed above, one gets better with practice. As long as they’re doing it deliberately and reflectively, the teacher gains a deeper conceptual understanding of the topic each time they teach that topic. As already mentioned, a teacher also gains greater insights into the common conceptions of students the more they work with students to explain a given topic. Teachers also get better at diagnosing student conceptions by asking the right questions and assigning effective tasks. Finally, with practice, the teacher is able to select and refine the materials, models, and metaphors that are the most useful as scaffolds for student learning.
