What Makes an Explanation in Science Lessons Effective?

A review of “Towards a framework for effective instructional explanations in science teaching” by Christoph Kulgemeyer (2019)

This paper provides an interesting review of the literature on effective explanations – a key element of science teaching and an exasperating gap in the academic literature. Kulgemeyer is clearly frustrated by the view common among researchers that:

“instructional explanations have sometimes been describes as representing an ineffective, transmissive view of learning.”

Despite this frustration, I think he compromises too much with the prevailing view:

“Instructional explanations should only be given if self-explnations are likely to fail.”

You could easily turn this around and say that: “until students are secure enough in their knowledge to be able to carry out self-explanation effectively, instructional explanations should be used.” Especially when he outlines the risk that students may fall for the “illusion of understanding” when self-explaining.

Nevertheless, Kulgemeyer explicitly refers to the similarities between his framework and direct instruction, so it is clear where his sympathies lie. I recommend reading his paper, if you can access it. If not, I have summarised his framework below (I have tried not to emphasise my own biases).

Kulgemeyer’s framework for effective instructional explanations in science teaching

1. Adapt the instructional explanation to your students’ prior knowledge.
2. Consider the following when you adapt your explanation:
   • the level of language you will use;
   • what examples and analogies you will use;
   • the level of mathematics you will use and
   • the demonstrations and models you will use.
3. Highlight the relevance of the explanation. This can be by:
   • showing how the new concept links to core concepts;
   • responding to student questions and
   • addressing misunderstanding.
4. Consider the structure of your explanation. For procedural explanations (i.e. how to use a technique) it is apparently more effective to given an example before you explain the rule. For content knowledge, it is more effective to explain the rule before you give the example. (note – this research comes from non-science education contexts… take it with a pinch of salt).
5. Use minimal explanations. This is my favourite part of the paper. Plan your instructional explanation to provide only the information that is needed and nothing more. Be “precise, coherent and free from irrelevant details.” Again, this is from non-science research, but it ties in well with cognitive load theory. Coherence means showing how the stages in an explanation are linked. Kulgemeyer recommends the thoughtful use of connectives such as ‘because’ and ‘before’. He also suggests ensuring that new vocabulary is used repeatedly in an instructional explanation.
6. “Instructional explanations should only be given is self-explanations are likely to fail.” You’ll have your own view on how likely this is.
7. “An instructional explanation is not finished after the presentation of information” (take that academics who think explanations are an “ineffective, transmissive approach”. Kulgemeyer emphasises a further two stages:
   • diagnose understanding and give remedial explanations – in other words, check for understanding and further adapt the explanation and
   • give opportunities to practise and apply the new learning.

There may be nothing new for you in this framework – great. Use it as a checklist of you like. New teachers might find it helpful as they plan their explanations. Either way, it illustrates that an effective instructional explanation requires significant thought and skill. It probably requires some level of planning and rehearsal. And it definitely isn’t just a transmissive lecture.