Scientific Method for Grades K-12
The scientific method provides the essential process of scientific discovery for any grade or experience level. Once learned, the scientific method becomes your constant companion for basic experiments and science fair projects. It’s an indispensable tool for building science skills and reaching sound scientific conclusions. The scientific method begins with a question… “I wonder...?” and can end with amazement and awe.
Follow the steps of the scientific method in order. Taken together, they provide a solid foundation for science exploration and discovery.
The Four Steps of the Scientific Method:
Step 1: Start with a question. What do you wonder about? What would you like to know? You might do some background research to learn more. It can help you define your question and decide what you want to discover.
Step 2: Form a hypothesis. Ask yourself: What do I think will happen when I conduct an experiment to answer my question? Write down your prediction, because what actually happens may surprise you!
Step 3: Conduct an experiment, making observations and tracking results. Set up a test experiment to see if your hypothesis is right or wrong. Make observations during your experiment and keep track of them by writing them down. Often is it necessary to repeat an experiment in the same way to be sure of your results.
Step 4: Come to a conclusion. Decide whether your hypothesis was right or wrong. What were the results of your experiment? Can you tell why it happened that way? Explain and communicate your results.
These principles can be used to study the world around us. You can study anything from plants and rocks to biology or chemical reactions using these four steps. Even young students benefit from learning how to use the scientific method.
For the Youngest Students:
The youngest students can study practical science using an even simpler version of the scientific method. Their natural curiosity can be guided through the scientific method to produce scientific learning. Try teaching the earliest grades the same steps, but making the language easier to understand.
- Wonder -- What do I want to know about the world around me?
- Think – What do I think will happen?
- Act – Test my idea. What happens?
- Say – Am I right?
These students can conduct their own experiments to learn about the world around them. For example, young students can study the states of matter by melting ice in the sun and shade. Before beginning, ask a student to predict what will happen to ice placed in the sun vs. ice placed in the shade. Then test his or her idea, check on the ice cubes over time, and ask the student to explain what happened. Was the student right?
In another example, young students could study chemical reactions by adding soap and food coloring to milk. Again, before beginning, ask a student to tell you what he or she thinks will happen when you add soap and food coloring to some milk. Test the experiment, watch for a reaction, and ask the student to explain what happened. Was the student right?
Spurred on by their natural curiosity, the youngest students can wonder, think, and observe. From the youngest ages, they can develop the ability to carefully observe and describe what they see. They can begin to develop the critical thinking skills needed to determine whether an experiment turned out how they expected—the beginning of scientific reasoning!
For Middle School or High School Students:
Older students can use the steps of the scientific method more independently to complete a science fair project or experiment on a topic in which they have an interest. Guide students’ learning with the following expansion on the last two steps of the scientific method, which require more advanced critical thinking skills.
Conduct an experiment, making observations, and tracking results.
Upper elementary, middle school, and high school students can design experiments, from simple to more complex, to answer their questions about the world around them. They can conduct these experiments, keep track of their observations, and analyze their results to see how well their hypotheses bore out.
In designing their experiments, these students should pay close attention to:
- Repeating an experiment. To be sure of your results, an experiment may need to be repeated multiple times, always in the same way. Did each repeat experiment produce the same results? The more times an experiment is repeated in the same way, producing the same results, the more sure you can be about the results.
- Controlling variables. A variable is a part of the experiment that can change. To be sure of your results, nothing should change when an experiment is repeated. Everything that could vary, such as the amounts of a substance, the kind of a substance, the time of day, or the environment, should be “held constant” or “controlled.” The more times an experiment is repeated in the same way—with no changes in the variables—the more sure you will be that the same experiment will always produce the same results.
- Changing only one variable at a time. Sometimes you may want to look at the effect of one change in the experiment on the outcome. In this case, it is important to change only one variable at a time. For example, if you wonder how the amount of water given to a plant will affect how fast it grows, only the amount of water given should vary for the plants tested. All the other variables—the soil, seed, amount of light, air temperature, etc.—should be the same for the plants in the experiment. Changing only one variable at a time allows you to attribute any difference in outcome to change in the one variable.
- Tracking results. What happened during your experiment? Identify all your variables and keep track of when you make observations and what you observe. Once you have all the information about your observations, called your data, you will be able to begin to put together an idea of your experiment’s outcome.
Come to a Conclusion.
What was the result of analyzing the results of all your observations? Did your experiment turn out as expected? Was your hypothesis right or wrong? If your results were surprising, you may not be able to come to a conclusion right away. You may want to reconsider all your variables, change a part of your design, and conduct another experiment, gathering more data. Arriving at a conclusion requires a critical assessment of the results of your experiment.
Science typically uses inductive reasoning rather than deductive reasoning. Deductive reasoning moves from general concepts to more specific information. But inductive reasoning moves from specific facts or observations to a general conclusion—just like the scientific method! For example, dissecting a flower and examining its individual parts teaches us about flowers in general. By examining something up close, science uses the critical thinking skills of observing, comparing, contrasting, and analyzing to make a general conclusion. The scientific method is a powerful tool to turn your questions into science discovery.