In this sequence of blog posts, I have been interested in two ideas: Teacher Clarity of Explanation and Pedagogical Content Knowledge (PCK), and thus far never the twain shall meet. But this is simply not the case. The difference between a good teacher explanation and a poor one is PCK. PCK is not just an understanding of your subject, but also of good general pedagogy. They inform one another. What I hope to do in this post is to exemplify this interaction. It begins with a general idea and will become more specific. So what do we need to know about what makes a successful teacher explanation.
“Understand that there are three factors in making a great explanation” Brown
At the heart of this is an understanding that every good explanation has important constituents: an explainer, a problem to be explained and some explainees (otherwise known as students). For each explanation, we must consider the problem the content itself presents as well as the knowledge and skills of the students so that the input is pitched correctly. We must display sensitivity both to the elements of the explanation the task itself demands and to the social situation of each teaching problem (“how do I teach x and y to Bob?”). In considering both we break down the problem the explanation presents so that the solution can be strategised about and planned.
To plan explanations, the following sequence seems prudent: (modified from Brown)
1. Analyse topics into main parts or ‘keys’.
2. Establish links between parts and consider their "best" sequence.
3. Determine rules (if any) involved.
4. Specify kinds or purpose of explanation required (context setting, interpreting, thinking, unpicking examples, describing, linking cause and effect and so forth).
5. Adapt plan according to learner characteristics
How well teachers identify the “Keys” of the explanation is central to their ability to explain; more effective teachers use a greater number of keys. Five kinds of “key” have been described. For research purposes, Brown and Armstrong assigned each key a cognitive level (1 the least, 5 the most), and I have left these in place as they found that good explainers tended to make higher cognitive demands on their students. This does not mean that they always use for example level 4 type explanations, however; they tend to use a wider variety, and in doing so include more at a higher level.
Explanation - Key types
Stating, defining, describing (simple e.g. what something is), classifying, designating.
Comparing, descriptive explanation describing process or structure in detail (e.g. how something works), interpretive (clarifies, exemplifies the meaning of things).
Reason giving, causes, motives.
Conditional Inferring (If…then…).
In order to best sequence may or may not be as straight forward as how the content presents itself. Beware that although certain content appears to naturally fit one of the sequences, it may not be the model that serves the learning of the content that best of all. This is particularly problematic if you aren’t aware of all the other options. For years, I’ve taught the topic of digestion by applying the logic of that the process itself begins in the mouth and so that my teaching should begin with the mouth and then work down through the digestive tract. The result of this was that, however well the students could identify the organs, they still struggled to explain the big idea of what digestion is. It was not until I re-jigged the sequence of teaching from a part-to-part-to-part structure to a whole-to-part structure did my students start to become competent in both. So now I begin with digested food molecules in the blood being absorbed from the small intestine because they are small enough to pass through its lining. This then naturally leads to a teaching sequence based on what happens to food to make the its molecules small enough to be absorbed. I now find that each organ that I teach about is easily linked to that original idea, giving my teaching a clearer purpose and that the students have a full understanding of the holistic process of digestion.
The all important alternatives have been succinctly summarised by Rothwell and Kazanas, who propose 9 approaches to sequencing instruction. Each sequence will serve a different type of content knowledge and will help to place each learning task into a context set by what goes before it. It also provides a useful set of options when you feel that your current order of explanation is not working for your students.
1. Chronological sequencing.
2. Topical sequencing.
3. Whole-to-part sequencing.
4. Part-to-whole sequencing.
5. Known-to-unknown sequencing.
6. Unknown-to-known sequencing.
7. Step-by-step sequencing.
8. Part-to-part-to-part sequencing.
9. General to specific sequencing.
Brown and Armstrong in Wragg Classroom teaching Skills
Rothwell and Kazanas 1998 Mastering the instructional design process: a systematic approach
E C Wragg and G Brown (1993) Explaining Routledge