Four teacher-tested approaches to help learners use self-explanation and build their confidence, engagement and understanding

When teaching my 14–16 and 16–18 students quantitative chemistry, I find they are able to follow steps to answer a specific problem type correctly as I introduce it. But it’s a different story when they’re faced with a mixture of different problems to solve – then they begin to struggle. This suggests that they follow procedures without a deep understanding of why individual steps are important.

One commonly suggested way to address this is to use worked examples when you introduce new problem types. However, unless students really study these examples, they are unlikely to produce the desired benefits. Such study needs to go beyond the frequently employed teaching strategies of talking through examples, modelling and providing students with step-by-step illustrations to refer to. 

Anticipatory self-explanation is more effective in building understanding than retrospective explanations

Worksheets and textbooks often include worked examples. But unless we ensure that students study them, the majority of learners dive straight into problem solving and are probably not actively engaging with the example provided. Michelene Chi outlined self-explanation as generating an explanation for oneself, in order to make sense of the learning material and this is one strategy learners can find beneficial in engaging with worked examples.

One commonly suggested way to address this is to use worked examples when you introduce new problem types. However, unless students really study these examples, they are unlikely to produce the desired benefits. Such study needs to go beyond the frequently employed teaching strategies of talking through examples, modelling and providing students with step-by-step illustrations to refer to. 

Worksheets and textbooks often include worked examples. But unless we ensure that students study them, the majority of learners dive straight into problem solving and are probably not actively engaging with the example provided. Michelene Chi outlined self-explanation as ’generating an explanation for oneself, in order to make sense of the learning material’ and this is one strategy learners can find beneficial in engaging with worked examples (pdf: bit.ly/4dRiI5W).

Here are four approaches you can use to encourage students to use self-explanation with worked examples and engage more deeply with problems.

Approach 1: model slowly with questions

  • Complete a worked example live (figure 1).
  • Outline the steps taken before asking students to explain them back.
  • Allow students time to study this example and to ask any questions they may have.

A worked example showing how to calculate the percentage mass of oxygen in water.

Source: Supplied by the author

Figure 1: complete a worked example, talking through the steps and asking students to explain them back

  • Complete a second example, this time in silence.
  • Give students time to consider each step and explain it to themselves.
  • Revisit to check for understanding. When asking questions, probe for more detail than you might think you need – e.g. in figure 2, ask ‘Where does 16 come from?’, ‘Why is it multiplied by 2?’.

A worked example showing how to calculate the percentage mass of oxygen in carbon dioxide.

Source: Supplied by the author

Figure 2: repeat using another question, but without speaking. Give students time to think deeply about the why behind each step

  • Finally, share a question with the class and allow time for them to think about how they would solve it, perhaps writing down their answers on mini whiteboards.
  • Work through the example, picking students randomly to explain the next step. A meta-analysis suggests that this anticipatory self-explanation is more effective in building understanding than the retrospective explanations in the worked example in figure 1.

Approach 2: practise anticipatory self-explanation

Goal-free problems support students in managing cognitive load as they aim to work out all that they are able to rather than having a specific goal in mind. You can use this to introduce reacting mass calculations once they have mastered the meaning of balanced equations and simple moles, mass and Mr problems.

Goal-free problems support students in managing cognitive load as they aim to work out all that they are able to rather than having a specific goal in mind. You can use this to introduce reacting mass calculations once they have mastered the meaning of balanced equations and simple moles, mass and Mr problems.

  • Provide students with an equation and table with a piece of data, such as the mass of one of the reactants, and ask them to complete as much as they can.
  • Once students have completed the goal-free table, get them to explain how they reached a particular answer. For example, when learners attempt ‘What mass of carbon dioxide can you make from the reaction of 100 g of oxygen with ethanol?’, you can ask ‘What steps did you need? Why was each step important?’.
  • Finally, provide students with a similar goaled, rather than goal-free, problem to complete.

Approach 3: annotate a worked example

Provide a minimally completed worked example for students to annotate. They should indicate what the person has calculated at each step and explain why each step helps towards the goal of the question.

Approach 4: check if it’s correct or incorrect

Approach 4: check if it’s correct or incorrect?

Provide students with a completed example and ask them to identify whether it is correct or incorrect. If correct they should explain the steps; if incorrect they should explain why. You can also apply this approach to written answers.

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Share examples of how to answer multistep questions to help deepen learners’ powers of thinking and create a culture of error so students are comfortable making mistakes. 

The aim of using self-explanation in all these approaches is to encourage students to avoid blindly following a procedure step-by-step by ensuring they understand the point of each step and why it matters. The main benefits I have observed in my classroom are learners being more confident to tackle unfamiliar problems, and better able to identify mistakes and self-correct.

Helen Skelton

Read more on deepening your learners’ thinking and understanding on the Education in Chemistry website: rsc.li/48f5heP