The Scientific Method for Grades K-12
For any grade or experience level, the scientific method contains the necessary technique for science discovery. Once learned, the scientific method becomes your constant companion for science fair projects and basic experiments. It’s an indispensable tool for building science skills and reaching sound scientific conclusions. The scientific method starts with a question– “I wonder...” ﹘and the answer is amazement and awe.
This method is broken down into a few simplified steps. Though you may not need every step for each experiment you do, as a whole, they provide a solid foundation for science exploration.
The Four Steps of the Scientific Method:
- Make observations – Look closely and think about what you are seeing. Collect data, or do background research. Making observations can also help you define the problem, or decide what you want to discover.
- Make a hypothesis – Put simply, say what you think will happen. Use the data or observations you have to predict what will happen. Write down the prediction. This is your hypothesis.
- Test your hypothesis – experiment to see if what you thought would happen did happen. You may choose to change one variable at a time and continue testing and experimenting.
- Make a conclusion – What happened? Record observations or share the data you have collected. Why did it happen? Use critical thinking skills to explain the results.
These principles can be used to study the world around us. We can study anything from botany to human anatomy using these four steps. Even younger students will benefit from learning how to use the scientific method.
For Younger Students:
Students from pre-K to second grade can experience practical science using an even simpler version of the scientific method. Try teaching the same steps from above, but make the language easier for early elementary students to understand:
- Look - What do you see?
- Think - What do you think will happen?
- Act – Test it out. What is happening?
- Say – Explain what happened. Why?
Many experiments with chemical or physical changes can be completed in this way. For example, study the states of matter by melting ice in the sun or shade, or study chemical reactions by adding soap and food coloring to milk, or add baking soda to vinegar. For the youngest students, some nature studies will focus on the first step, looking or observing. The ability to carefully look at something and describe what you see is an important science skill.
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 with a topic they have a definite interest in. Guide students’ learning with the following expansion on the last two steps of the scientific method, which require the most advanced critical thinking skills.
Test your hypothesis – This is the hands-on part where you design, perform, and analyze experiments to test your hypothesis. By repeating the experiment, you’ll have more results to compare and draw accurate conclusions from. This principle applies even when completing experiments from a curriculum.
Controlling variables is essential for getting accurate results. Variables for a plant growth experiment could include kind of seed, amount of water, position in sun, as well as amount of light. If you are testing the effect of less light, this is a changing variable. At the same time, make sure constant variables don’t change between experiments, i.e. all the bean sprouts came from the same packet of seeds; each plant receives an equal amount of water; plants are placed in the same position outside. In general, testing only one changing variable at a time is best.
Another key is multiple test subjects. For example, don’t cover just one bean sprout with a paper bag for an hour and compare it to another bean sprout. Use more than one plant as your test subject, and use more than one plant as your control group of “normal” plants. This especially holds true for science fair projects.
Make a Conclusion – If your experiments turn out as forecasted, then your predictions were probably based on sound scientific principles. If they were off target, evaluate your data and start again with a refined hypothesis. Usually if something goes wrong, you should check your variables.
Making a sound conclusion requires critical thinking. Science typically uses inductive reasoning. Inductive reasoning moves from some specific facts or observations to a general conclusion. By examining something up close, we can use critical thinking skills such as comparing, contrasting, and analyzing what we see to make a general conclusion. For example, by examining and dissecting one flower, we learn about the parts of plants or flowers in general. This is the opposite of deductive reasoning, which moves from general concepts or observations to more specific concepts. Both approaches of looking at things (seeing the big picture and noticing small details) are important. The scientific method is uniquely designed to help guide inductive reasoning from noticing small details to seeing a bigger picture.