All teachers explain new content and ideas to students and the best presentations are concise, appropriate and engaging explanations: neither too short nor too long; neither too complex nor too simple. According to the research evidence, the following features of explanations are your best bets for helping students to understand and learn new ideas.
Explanations that are linked to what we already know. Learning depends on the connections that learners make between new ideas and what they already know. Prior knowledge is structured in schemas so when explaining a new idea, teachers will activate that prior knowledge and connect new ideas to it so that new knowledge is accommodated into and extend existing schemas. In linking new ideas to old ones, teachers may compare, contrast and categorise to help students’ understanding.
Explanations that include models, analogies, representations and examples help explain and convey hard ideas. Teachers commonly use analogies in their explanations to compare a new idea to one that is already known by students. Models and representations help learners visualise abstract concepts and help make them concrete. These devices are effective only if teachers elaborate on them, and direct student attention to the crucial similarities and differences between the analogies, models and representations and what is to be learned. Examples are helpful to use in any explanation and equally helpful are non-examples and borderline cases: the exceptions and hard cases that define the boundaries of a rule or definition. Even with the best explanation, some students still may not get it and so teachers need to have more than one way of explaining or presenting the idea, and multiple examples so that they can keep going until the student does get it.
Explanations address common misconceptions and sticking points that students should be aware of. For experienced teachers, student misconceptions can be predictable and inevitable. In their explanations, teachers will anticipate and address these misconceptions directly and explicitly, both by exposing and challenging the misconception and by presenting the correct conception clearly and directly.
Explanations are carefully paced. Understanding new ideas can be impeded if students are confronted with too much information at once. In presenting material, teachers should pay attention to the issue of ‘cognitive load’ by limiting the number and complexity of new elements, breaking complex ideas or procedures into smaller steps, helping students to assimilate concepts into and extend existing schemas and minimising extraneous, irrelevant or distracting input, from either content or environment.