Enjoy teaching scientific method with some simple experiments. Your students will soon understand how to conduct a fair test.
The Scientific Method
The scientific method allows us to conduct scientific investigations. Think of it as a flexible set of organized steps. A full-blown set for intermediate-grade students might look like this:
- Ask a question.
- Conduct research.
- Design an experiment. (Design a fair test. Test the hypothesis.)
- Make observations.
- Collect data. (Record results.)
- Draw conclusions.
- Share results. (Communicate.)
Simple inquiry in the classroom might only include these steps:
- Ask a question.
- Test the hypothesis.
- Record results.
- Draw conclusions.
Scholastic offers a great Study Jam video and quiz to explain how to use the scientific method.
The Fair Test (or How to Design an Experiment)
Every kid should understand how to carry out a fair test. It allows us to trust the results of an experiment. Scientists (even those who are nine years old!) must:
- Compare. To test a hypothesis, compare two or three situations. For example, will this plant grow better with fertilizer or without?
- Control variables. Everything must be controlled, or kept exactly the same. For example, the plants, pots, soil, sunlight, temperature, water, and so on must be the same.
- Use tools. Measure everything carefully with balance scales, graduated cylinders, rulers, etc.
- Replicate. Do the experiment over and over to be sure you come up with the same results.
Would you like a quick, easy way to teach this? Watch this 4-minute video. It shows how to conduct a fair test using a simple vinegar/baking soda experiment. To practice, play this game from Splash ABC.
How to Enjoy Teaching Scientific Method
Classroom experiments are fun for everyone! No need for anything extravagant. The simplest experiments can be the most profound. I like to start with an easy evaporation experiment.
Question: Which will evaporate more, water in an open or closed container?
Research: Water in an open container will continue to evaporate until it is all gone. When water is placed in a closed container, it also evaporates. This happens only until the air between the cover to the container and the water surface is saturated, or full of water vapor. Then the water molecules begin to return to the water at the same rate that others are evaporating.
Hypothesis: A small amount of water will evaporate from a closed cup, and more will evaporate from an open cup.
Designing & Conducting a Fair Test:
- Procedure – (1) Measure 50 milliliters of water into six cups. (2) Cover three cups in plastic wrap. Leave the other three cups open to the air. (3) Wait two days. (4) Measure the amounts of water in each cup. Record.
- Variable – open or closed cup
- Controls – same cups, same cover, same liquid, same temperature, same light, same humidity
Observations: An average of 38 milliliters of water remained in the open cups. An average of 50 milliliters of water remained in the closed cup.
Conclusion: Water in an open cup evaporates, but water in a closed cup does not.
Scientific Method Freebie
After some guided experiments, students are ready to try it themselves. I like to give them some basic information. Then they can design their own fair tests! Click here to download this freebie on gravity and air resistance.
Use this strategy over and over again! Ask students to design investigations on any concept you’re studying.
The Complete Unit
You can find a complete introduction to the scientific method in my Teachers pay Teachers store. It includes a PowerPoint presentation, lesson plans, posters, and a different prompt for scientific investigation.
I post new ideas, activities, and free downloads every week. Click here for an index (and to see what’s coming soon!)
Enjoy teaching scientific method!