Testable Science Fair Ideas

To execute a successful science fair project, the hypothesis must be testable. Experiments vary by grade level to include those that offer good starting points for coming up with even more extensive experiments. Pick a topic that interests you to get the most out of your science fair project.

Since you may have been yelled at for playing with worms as a child, bring out the child in yourself by testing the effects of colored light on earthworms. Send away for a worm habitat kit, which includes live worms, soil and food. Set up your worm habitat and begin by testing the effect that no light has on your worms. Insert a light shield on the habitat for one day and record your findings. Focus on the worms' level of activity and their location within the soil–e.g., whether they burrow or lay on top.

Put colored transparencies over the habitat and record these findings again before switching to a new color each day. Conclude whether certain colors affected the worms' activities.

Students may be interested in testing the force of magnets. A testable science fair project involves testing the force of a magnet through a variety of materials. First test the force of a magnet through plastic by putting a paper clip into a sealable plastic baggie. Try to move the paper clip in the plastic bag using a small magnet. Record your findings.

Dangle a paper clip off a table by tying a piece of string to the paper clip and taping it down to a table. Hold a single sheet of paper over the magnet and move your small magnet toward the paper clip. Test the force of a magnet through paper by observing whether the paper clip moves toward the paper as you move the magnet closer.

Finally, put a paper clip into a clear cup of water. Hover your magnet over the glass of water in an effort to move the paper clip. Record your findings regarding the magnet's strength through water.

Test a variety of liquids to determine their effect on plant growth. Pot four plants and feed each with a different liquid, such as water, milk, orange juice and vinegar. Track each plant's growth with a ruler and take visual evidence with a digital camera.

Go a step further with this experiment by testing other liquids, like soda or flavored water.