Class inclusion

• An advanced classification skill where we recognise that classes of objects have subsets and are themselves subsets of larger classes
• Pre-operational children usually struggle to place things in more than one class
• Piaget's Task

  Children are shown 7 pictures of cows - 4 black and white, and 3 brown

  Piaget then asked 'are there more black and white cows or are there more cows' (children may say there are more black and white cows as they're focused on what they can see, not larger classes)