Four top tips for scaffolding chemistry concepts

Every class is a mixed-ability group to some extent. So good teaching must involve high-quality differentiation strategies. Setting by student ability is common in chemistry classrooms up to age 14. However, my school has moved away from setting due to the lack of evidence supporting its benefits. This change challenged my teaching because it forced me to confront differentiation head on.

One way to differentiate effectively in chemistry is to scaffold learning for all students, and to remove some scaffolding for individuals as they progress. Learning then becomes more challenging at the student’s own pace. Good scaffolding makes learning accessible to all students and is easy to remove as students ‘master the scaffold’. Once students master the scaffold, they can concentrate on mastery of the underlying concept.

Designing high-quality resources to scaffold learning takes creativity, deep knowledge of students’ prior conceptions and time. In my view, the best way to meet these challenges is to collaborate within your department. I’ve spent a good deal of time thinking about ways to scaffold chemistry with my colleagues. Here are my top tips:

1 – Construct thinking maps

Thinking maps are excellent visual scaffolds for learning complex concepts in chemistry. One of the most useful is a flow map, which leads students from simpler concepts (such as the charges and sizes of sodium and magnesium ions) to explain a more complex one (their relative melting points) in a logical order.

Place the complex concept at the top of the flow map and a series of incomplete sentences below it that decrease in complexity. Students complete the missing parts of the statements from the bottom to the top.

In your class

Download a flow map (MS Word or pdf) that helps students build reasoning towards the concept that magnesium has a higher melting point than sodium.

Working through their reasoning in stages helps students to ‘chunk’ their learning. As students grow in confidence you can remove the scaffold. You can ask them to design a similar map (to compare potassium and calcium), explore a related problem (such as lithium and sodium), or use data to work down a flow map instead. Try removing their map and asking students to complete long answer questions to keep them challenged throughout a lesson.

2 – Vary the approach

Using different methods to achieve the same outcome is a mainstay of excellent chemistry teaching. I use this strategy to teach ionic formulae. Initially, give students ion cards. The size of a card is proportional to the charge of the ion it represents and students need to use the correct number of each ion card to form an ionic compound. Next, students use the criss-cross method to represent the ionic compound. And finally, students draw the atoms and show the transfer of electrons.

Sometimes students struggle with the first method, but the concept starts to click with the second. When they look back at the first method they can understand why it also worked. Linking different methods helps them learn the concept deeply. This method can be applied to many topics; the trick is to move students on once they have mastered each method so they keep learning.

3 – Use stepping stones

Stepping stone activities are excellent because they take students from something they know to something unfamiliar in stages. Students construct new learning embedded in their existing framework of knowledge.

This strategy works particularly well for practical reasoning. Give students a familiar practical task. Once they describe or follow the correct method, remove some of the familiar apparatus and replace it with something else, so they have to adapt their ideas.

I have used this to get 14–16 year old students to derive the method of titration and carry out the experiment with great success. Students had to work out the number of drops of hydrochloric acid required to neutralise 5 ml sodium hydroxide in a beaker with a pipette and indicator. They iterated their method each time I changed a piece of apparatus.

4 – Set learning menus

I’ve been a ‘learning menus’ convert since my school ditched sets. I particularly recommend them for summary and revision lessons. The idea is students have a range of tasks to complete, which can be done in any order. This lets students scaffold their own learning.

Students begin with the tasks they find accessible, and move on to tasks they find more challenging. You can set learning menus in a variety of ways: with a simple 4 x 4 box of tasks to choose from; or a required number of tasks students must complete from each topic or level of difficulty. Students love the freedom to choose their own tasks, and you can encourage individuals to ensure they are challenging themselves.

Not every teacher works with mixed-attainment classes, but this does not mean differentiation goes out the window. Lessons with good scaffolding allow all students to be engaged, right from the start. And, as the scaffolding is removed, all students are stretched and challenged.