Models are systematic simplified representations of physical systems which are used to describe, represent and explain the fundamental mechanisms in nature. Although such models can be expressed in a number of ways, they are essentially conceptual in nature. Science proceeds through the construction and refinement of models, and learning in science entails developing understanding about natural phenomena by constructing models, as well as learning the process of developing and refining those models. Model construction provides a hands-on experience that may substantially improve performance in science processes. Model construction is an appropriate method for teaching advanced concepts.There is growing recognition that models play a fundamental role in the comprehension of science concepts. The general definition of model is a simplified representation of a system, which concentrates attention on specific aspects of the system. Consequently, model building process can be expressed as an organizer for understanding scientific knowledge and process. Some familiar examples of scientific models include the particle model of matter, a light ray model, the water cycle, and a food web model that shows interactions between organisms. Models can be physical such as the atom model or conceptual, such as the water cycle model.
When considering the volcano and the butterfly models, we see that they cannot easily be used as scientific models, since they do not accurately predict or explain the phenomenon
of volcanic activity or the cyclical nature of the butterfly life cycle. They represent an idea but they do not allow us to test an idea or extend it. The solar system model describes the order and type of planets in our solar system, so it is helpful for understanding these components, though the model is limited in the sense that it does not always accurately represent other aspects such as the motion around the Sun and the distances between planets.
Even better than knowing about powerful models is knowing and doing scientific modeling. What we mean by modeling is the experience of constructing, using, evaluating, and revising scientific models and knowing what guides and motivates their use. When students are engaged in scientific modeling, they are able to notice patterns and develop and revise representations that become useful models to predict and explain--making their own scientific knowledge stronger, helping them think critically, and helping them know more about the nature of science.
MODEL-BUILDING IN SCIENCE
The scientific method is a procedure for the construction and verification of models. After a problem is formulated, the process consists of four stages.
As mentioned previously, a model contains the essential structure of objects or events. The first stage identifies the relevant features of the real world.
The symbols in a formal language are given meaning as objects, events, or relationships in the real world. This is the process used in translating "word problems" to algebraic expressions in high school algebra. This