There are (at least) three steps to expertise:

1. Learn the basic knowledge – students cannot organise what they do not know

2. Develop flexible knowledge, which students can access in response to many relevant cues

3. Organise and link ideas to create mental models which can be applied to solve problems/answer questions/whatever

If we are to organise and link ideas, we need to:

• Identify disciplinary structures (perhaps 4-5 for a subject of which 1-2 will be relevant in a specific topic)

• Place key ideas in hierarchies (2-3 for a topic)

• Identify the most important links (no more than five for a topic)

Once we have chosen the most powerful organising structures we need to develop students’ knowledge of them.