Strengthening teaching and learning of energy: Misconceptions and teaching models

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1 The National Strategies Secondary 1 Strengthening teaching and learning of energy: Misconceptions and teaching models Alternative models for teaching energy The use of precise terminology when teaching energy has a significant part to play in developing pupils understanding about the conservation of energy, particularly in relation to the application of ideas about energy. Pupils become confused if we are not consistent in our use of terminology when teaching energy topics or energy-related aspects of other topics. There are two commonly used ways of teaching (teaching models) energy: transformation of energy and energy transfer. Neither is entirely right or wrong. The energy transfer model has greater potential to support pupils explanations of events and phenomena during Key Stage 3 and 4 than the transformation model and so it is the sole model used in the revised science Framework and programme of study. Transformation of energy According to this model, energy takes on different forms for example, chemical, heat, light and so on. Energy is transformed or changed from one form or type to another when a change occurs. Typical language used with this model would be: The chemical energy in the battery is transformed into electrical energy in the wires and then to light and heat energy in the bulb. The light energy from the Sun is changed into chemical energy in the leaf. Chemical energy in the reaction is changed into light and heat. The chemical energy in the weightlifter s muscles is changed into kinetic energy when the bar is being lifted and is changed into potential energy at the top of the lift. Crown copyright PDF-EN-02

2 2 The National Strategies Secondary Energy transfer With this model, the energy is located in one place, and when something happens, energy is transferred from that place to another by a process. Typical language used with this model would be: The energy in the battery is transferred to the bulb by electricity and then from the bulb to the surroundings by light. Some energy is transferred to the surroundings by heating. Energy from the Sun is transferred to the leaf cells by light. Energy is transferred from the reacting chemicals to the surroundings by heating and light. A weightlifter transfers energy from his muscles to the bar by lifting (moving) his arms. Alternative ways of teaching (teaching models) about energy at Key Stage 3. Energy transformation Light Electrical Chemical Heat Energy transfer Electric current Light Surroundings Cell Bulb Heating In the transformation of energy teaching model, the energy is present in both places and processes (for example, there is chemical energy in the cell and electrical energy in the electric current in the wires). The energy is changed from one type to another by devices (the bulb converts electrical energy into heat energy and light energy). If we relate these two models to how we might explain what happens when a torch is switched on, it becomes clear that, according to the energy transfer teaching model, it is the location of the energy that is important. The energy is transferred from place to place by processes such as heating and light PDF-EN-02 Crown copyright 2009

3 The National Strategies Secondary 3 The terminology of energy transfer The terminology of energy transfer appears more complicated than that used for the transformation of energy because it describes the process involved as opposed to just naming types of energy. Indeed, some of the terms that relate to types of energy (which are also generally used in the transformation of energy teaching model) refer to processes and/or stores of energy (energy resources). The terminology of the energy transfer teaching model distinguishes between processes and stores of energy. There is an added complication, caused by the English language, in that similar words can be used in both teaching models, such as sound and light! If you look at the two lists of words below, the subtle differences between the two sets of terminology become more evident. These lists also provide a good indicator of which model is being used in published texts. Transformation heat light sound electrical kinetic chemical potential (elastic and gravitational) nuclear Transfer heating light sound electric current stored stored stored stored You may not think of kinetic energy as stored energy because it involves movement, but a flywheel in a friction toy or a steam engine does store energy. Energy in moving objects is often transferred to the surroundings because of friction. Pupils often say that energy is lost, which is incorrect and a common misconception. When the transformational model is being used you will notice terminology such as transform, change and convert commonly used in textbooks and by other teachers. Crown copyright PDF-EN-02

4 4 The National Strategies Secondary Limitations of teaching models The transformation of energy model identifies energy as changing from one form or type of energy to another. When using this model we are considering energy as a material that can take many forms. Most teachers will be able to name these energy forms chemical, thermal, potential and kinetic energy, for example. This model is descriptive and therefore accessible to many pupils. Some science departments prefer to use this model rather than the transfer of energy model in Year 7 to help pupils make progress from concrete ideas in Year 6 to a more abstract idea of energy in Year 7. Some science departments find that using a transformer toy, as an analogy of the transformation model, is helpful because the toy can take on different forms, yet it is clearly still the same toy. Similarly, while the forms of energy in this teaching model may appear to be different, they are actually manifestations of the same energy. Like most teaching models, the transformation of energy model has its limitations. When pupils encounter more challenging events or phenomena they will need a more sophisticated explanation. The main limitation of the transformation of energy teaching model is that it can restrict pupils progress from a simple understanding of energy in Year 7 to understanding and explaining more complex events and phenomena, using conservation of energy as an accounting system, in Year 9 and on KS4 courses. The model may also reinforce some common misconceptions, such as: heat and temperature are the same heat is a substance that flows like a fluid or energy generally is a kind of stuff heat is static and occupies a particular space food and fuel are energy rather than an energy resource and a store of energy. It is important for you to be aware of the strengths and weaknesses of any teaching model you use. This is because, for pupils to make good progress, they need to be able to identify the strengths and limitations of models. So you will need to help them to evaluate models. Look at the thread from AF1, Thinking scientifically, and the APP criteria that illustrate this: 8 Describe or explain processes or phenomena, logically and in detail, making use of abstract ideas and models from different areas of science 7 Make explicit connections between abstract ideas and/or models in explaining processes or phenomena 6 Use abstract ideas or models or multiple factors when explaining processes or phenomena Identify the strengths and weaknesses of particular models 5 Use abstract ideas or models or more than one step when describing processes or phenomena Explain processes or phenomena, suggest solutions to problems or answer questions by drawing on abstract ideas or models 4 Use simple models to describe scientific ideas. The full set of APP criteria can be found at (choose Science from the Secondary list, then, from the Chapters list, 3 APP Materials, then, from the Attachments and resources area at top right, select the document Assessing pupil s progress in science at Key Stage 3: Assessment guidelines) PDF-EN-02 Crown copyright 2009

5 The National Strategies Secondary 5 Take a look at the following three explanations. Which model would you suggest is being used for each one? Card A Wind-up mouse Card B Torch Laurence Mouton/Photolibrary Pixtal Images/Photolibrary A. Potential energy stored in the person s muscles is changed to elastic potential energy in the spring. Potential energy in the spring is changed to kinetic (moving) energy and some sound energy when the mouse is moving. B. Energy from the person is transferred to the spring when it is wound up. Energy is then transferred from the spring to the mouse while it is moving. Some of the energy stored in the spring is transferred to the surroundings by sound. C. Potential energy from the person s muscles is transferred to the spring when it is wound up. When the mouse is released the energy stored in the spring is changed into kinetic (moving) energy and some sound energy. A. When the circuit is switched on, chemical (stored) energy in the battery is changed into electrical energy in the wires and then into light and heat energy by the bulb. B. When the circuit is switched on, the energy stored in the cells is transferred to the bulb by an electric current in the wires. Energy is then transferred from the bulb to the surroundings by heating and light. C. When the circuit is switched on, chemical energy from the battery is transferred to the bulb by electrical energy in the wires. Energy is then transferred from the bulb as light and heat energy. The answer is that the first explanation uses the transformation model, the second uses the transfer model and the third a mixture of both (which is likely to be confusing for pupils). It is important to use explicitly the correct energy transfer terminology when explaining phenomena to pupils. Opportunities for these explanations can often be found in contexts such as heat, light, sound, electricity and biosystems. This doesn t mean that you have to rewrite lesson plans but, rather, ask appropriate challenging questions while pupils are working on that topic. This way of adapting your teaching is developed further in Energy: Using energy transfer when explaining light. That you are using the energy transfer model can be made more explicit when explaining a range of phenomena by making some simple modifications to learning objectives. This will increase the level of challenge for pupils, too, by, for example, using energy transfer to describe and explain the properties of light. This is also explored in Energy: Using energy transfer when explaining light. Crown copyright PDF-EN-02

6 6 The National Strategies Secondary Task 2: Transfer or transformation? 1. Select some of the textbooks in your department and, using the examples above, try to identify the model(s) that have been used. 2. You may also wish to try this with an able group of students as an extension activity, allowing pupils to demonstrate performance at levels 6 and 7 within AF 1, Thinking scientifically. 3. Alternatively, introduce this analysis of textbooks as an activity for a forthcoming department meeting. You can read more about these teaching models for energy in appendix 4, Teaching about energy by Robin Millar PDF-EN-02 Crown copyright 2009

7 The National Strategies Secondary 7 What are the misconceptions? Misconceptions are views held by pupils (and adults) that do not fully coincide with scientific views. They can be held by a large proportion of the population or by just one individual, based on personal experience. Often they are developed through everyday talk. Misconceptions may be: linked to everyday use of language constructed from everyday experience and usually adequate for everyday life personal or shared with others used to explain how the world works in simple terms similar to earlier scientific models (such as the Earth is flat) inconsistent with science taught in schools resistant to change. Many ideas that pupils hold about the world around them come from sensory experience. They construct a framework from these events that is coherent and fits their experiences, but which may be very different from the scientific view. The scientific explanation can then seem counter-intuitive, such as that wood is produced from carbon dioxide and water. The most important feature of misconceptions is that they often inhibit further conceptual development. Those evident in the oral and written work of Key Stage 3 pupils can persist into Key Stages 4 and 5, with examiners reports highlighting a number of them year on year. For example, pupils misconceptions in exams identified in a recent examiner s report included: a nucleus in a blood cell is used to store food the image forms on the cornea a scab is responsible for growing new skin capillaries move nearer to the surface of the skin to cool the body infrared light is responsible for a tan organic is taken to mean natural and not understood in its chemistry context magnetism is thought to be involved in chemical bonds heat rather than hot air is thought to rise. It is worth recognising that, in many cases, pupils can hold both the misconception and the scientific idea at the same time and may use different ways to explain events in different situations. It is rare, however, for pupils (and adults) to be explicitly aware that they are doing this. Even when presented with new evidence, the existing ideas may be resistant to change and pupils may modify the evidence to fit into their existing model. Crown copyright PDF-EN-02

8 8 The National Strategies Secondary Task 3: Some questions about misconceptions Indicate whether you think the statements in the table below are true or false by putting a tick in the relevant column. Don t take too long to think about each statement your first thoughts will do. Compare your responses to those given in appendix 5. Identify where your initial responses were different. Use this as a basis for discussion with a colleague more experienced in successfully teaching energy to pupils. Statement True False Comment 1. Energy is a kind of stuff that is transferred from place to place when something happens. 2. Energy causes events to happen. 3. Heat and temperature are the same thing. 4. Heat is a form of energy. 5. Heating is a process of energy transfer. 6. Electricity is an energy source. 7. An electric current transfers energy. 8. Energy is dissipated but not lost when appliances are used. 9. Sound energy is transferred to the surroundings by vibrations. 10. Lighting is a process of energy transfer. 11. Respiration uses energy. 12. Photosynthesis makes energy. 13. Energy is a fuel. 14. The world is facing an energy crisis. 15. Chemical reactions cause energy to be transferred. 16. A car transfers all of the energy from the petrol to heating the surroundings PDF-EN-02 Crown copyright 2009

9 The National Strategies Secondary 9 Task 4: Is it terminology or the teaching models? Look at the pupils statements about energy below. For each statement, consider whether it illustrates: a lack of precision in the terminology used an underlying misconception about the scientific ideas both. Compare your responses with the comments in appendix 6. Pupils statements 1. There are many ways of transferring energy, e.g. food, wires, plugs, springs and sunlight. 2. A car uses petrol energy to make it go. 3. As the clockwork car moves it uses up the energy in the spring. When all the energy is used it stops going. 4. Plants make energy from the Sun. 5. I burnt up the energy from the chocolate when I ran home. 6. Energy from gravity makes the ball fall down. 7. Energy makes the rocket go up. 8. As you get further from the torch the light gets dimmer because the light energy is running out. 9. The two beakers of water have the same heat. 10. Joules and calories are sorts of energy. In general, pupils hold relatively few fundamental misconceptions about energy. Some of these are: energy is used up or created energy is a kind of stuff fuels are energy heat and temperature are the same thing energy makes things happen. In many other cases, incorrect answers to questions reflect an imprecise use of terminology by pupils rather than fundamental misconceptions. Follow-up task Now look at your responses to task 4. How could you best respond to pupils in your class who make these comments to help counter their imprecise language or misconceptions? Crown copyright PDF-EN-02

10 10 The National Strategies Secondary Reflection The science Framework ( and choose Secondary Frameworks from the Secondary list, then Science Framework from the next list) contains a number of barriers that might prevent pupils making progress in all areas of science. These barriers are mentioned in Energy: Introduction. Often, they are misconceptions that pupils (and sometimes teachers) hold. It is important to recognise that we all have wobbly bits in our own understanding of science and we might convey these to pupils, consciously or unconsciously. Consider, for example: the strategies you use to teach something you are less confident about have you ever taught any science you thought was true and then found it wasn t? Look back at the barriers to learning about energy given in Energy: Introduction. Be honest and identify those that could be barriers for you. Select one or two misconceptions and think about the difficulties these could cause for future learning. For example, the misconception that hot objects can cool down without something else around them getting hot (energy is just lost ). If you want to find out more, a good overview of the research into children s ideas can be found in Making Sense of Secondary Science by Rosalind Driver, Ann Squires, Peter Rushworth and Valerie Wood- Robinson (Routledge, 1994). Acknowledgements Photograph of a wind-up mouse Laurence Mouton/Photolibrary. Used with kind permission. Photograph of a torch Pixtal Images/Photolibrary. Used with kind permission PDF-EN-02 Crown copyright 2009