Models and analogies

Where models and analogies are useful in teaching  Objects that are too big, e.g. solar system  Objects that are too small or not easily seen, e.g. cell, heart  Processes that cannot be easily seen directly, e.g. digestion, erosion  Abstract ideas, e.g. particulate nature of matter, energy transfer

Models can be grouped into either:  Scientific models – these are consensus models agreed by the scientific community. They are often pictorial, like the arrangement of particles in solids, liquids and gases, although sometimes they are mathematical representations.  Teaching models – ways of explaining abstract phenomena. They can be pictorial representations (e.g. a diagram of the eye), three-dimensional (e.g. molecular models) or computer animations (e.g. to illustrate the particulate nature of matter).  Historical models – explanations used by scientists in the past. These change as new evidence becomes available (e.g. phlogiston theory).

Using models and analogies Step 1 Step 2 Step 3 Step 4 Pupils can use everyday analogies to explain their understanding of some scientific ideas Pupils can devise models to explain their observations, data or ideas. They know that different models are used in science to explain the same phenomenon Pupils can identify strengths and weaknesses in some of the analogies and scientific models used, using a range of criteria. They are beginning to see the importance of creative thinking in science. Pupils can select an appropriate model for an explanation. They can explain why the model is the most appropriate. They can devise more than one model for a situation by thinking creatively.

Moving from stage 1 to 2  Use visual prompts to stimulate thinking about a scientific ideas.  Show pupils how to use and develop simple everyday analogies or models to explain a process and/or concept.  Pupils select appropriate models to suit a given concept or observation.

Examples  Visual Prompt – different types of rock  Concrete Analogy – different types of biscuits or cookies  Visual Prompt – diffusion of gas particles demonstration  Concrete Analogy – crowds leaving a tube station or a football match

Moving from stage 2 to 3  Make the use of models and analogies the focus of the lesson through lesson objectives and learning outcomes that are shared with the pupils.  Evaluate the strengths and weaknesses of the model. Pupils work out which is the preferred ‘best fit’ model and decide on the rationale for this decision.

Moving from stage 3 to 4  Teachers encourage pupils to extend their explanation of the strengths and weaknesses and how to manipulate a model to make it more appropriate.  Pupils study a range of how real-life examples of the use of models have changed over time as a result of creative thinking.  Pupils should extend their use of models to generate other ways of explaining the observation or data that may be at odds with current scientific knowledge and provide a reasoned argument as to why this is also a plausible analogy

A torch has a circuit in it. Use the diagram of a torch to describe and explain your ideas about energy and electricity

How could this be improved? Would this work for a parallel circuit? Can you make another model?