National Science Standards – The “Unifying Concepts of Science”  

Our National Science Standards now include a content standard that focuses on the “unifying concepts” or "big ideas” of science.  These overarching concepts provide students with powerful ideas to help them understand the natural world.  Unifying concepts are often principles and/or patterns that permeate different areas of science in ways that can help us to organize and comprehend. A “big idea” approach to science helps students to see the interrelatedness of scientific concepts and it provides the opportunity for them develop a foundation for deep understanding and reasoning. 

There are only 5 unifying processes or “big ideas” that are identified in the National Standards. They include: 

1. Systems, order, and organization.
2. Evidence, models, and explanation.
3. Change, constancy, and measurement.
4. Evolution and equilibrium.
5. Form and function.

Systems:  Nature is made up of many systems that are related and/or connected in some ways. A system is a whole that is composed of parts arranged in an orderly manner according to some plan or function.  Our body makes up a system, the planets around the sun make a (solar) system, and each classroom in our school makes up a system.  Children can begin to understand systems by considering the parts that make up a system, the purpose of a system, and the changes that occur in a system. Having kids consider a classroom as a system or an aquarium as a system is a good place to begin this discussion.

  Summary:  Nature is composed of many interrelated systems.    

  Evidence, Models, and Explanation:  Nature behaves in predictable ways and searching for explanations is one of the most important functions of science.   We must teach children how to use evidence and models to develop explanations that help us to understand our world. Models are used in science to represent other things that might be difficult to see or measure.  Models are a difficult concept for young children to grasp.

  Summary:  Nature is predictable and we can use evidence and models to develop explanations to understand our world. 

  Change, Constancy, and Measurement:  The natural world is continually changing and children should be made aware of these changes. For example, children can be asked to observe changes in the seasons and changes in the position and apparent shape of the moon.  Although change occurs, there are many patterns that are repeated constantly over time. For example, the earth rotates every 24 hours, ocean tides come twice a day, and caterpillars develop into butterflies.  Measurements can be used to document changes and consistency over time.

  Summary:  Nature is constantly changing but there are many repeating patterns.

Evolution and Equilibrium:  All organisms have their own distinctive characteristics and so there is a great deal of diversity in nature. These characteristics are inherited from one generation to another and nature selects the characteristics (adaptations) that provide advantages for survival.  While both organisms and their environments change, natural systems tend to be balanced (in equilibrium) over time. Children can quickly come to appreciate the wonderful diversity found in nature and can gradually consider how traits are inherited over time.  

Summary:   Organisms are diverse and nature selects the characteristics (adaptations) of organisms that provide advantages for survival.

  Form and Function:  A relationship usually exists between the form or an object or organism (how it looks, sounds, feels, smells) and the function of the object or organism (what is does).  Children can learn to infer the functions of things by closely observing their forms. For example, they can infer what a mammal eats by observing their teeth, or what a bird eats by examining the structure of their beaks.

Summary: There is a relationship between the form of an object and it’s function.

 With the advent of the Internet and the continuing avalanche of new information, it should become increasingly clear to us that we cannot realistically be expected to teach the details of what is now known about science.  Perhaps the details and facts, so often the focus of our instruction in science, should only be stressed to the degree that help us to illuminate and better understand the key "big ideas" of science.  Our efforts as science teachers could then focus on providing students with strategies for thinking through ideas, encouragement in transferring their knowledge from one situation to another, and practice in applying scientific approaches to solve real-world problems.   In doing so, we can prepare our students to understand key unifying concepts and develop the new “big ideas” for the future of science.