Follow the bouncing ball: the best offense for a winning science project is a step-by-step plan - write a procedure: includes two sample procedures - Special Issue: Science Project Success Guide

Science World, Sept 20, 1996 by Maria L. Chang

Getting a good science project together takes time and patience. Sometimes the best ideas can come to you when you take a break!

For instance, say you grab a basketball and shoot a few hoops with a friend. While dribbling the ball, you notice something: The ball's not as bouncy as it was last summer. And you just pumped air into it last week. What could be wrong? "Maybe it was that cold front that passed through last night," says your know-it-all friend.

Sounds like an experiment in the making. Does a ball bounce higher in warmer weather? To put it scientifically: What is the effect of temperature on how high a ball bounces? To find an answer, design an experiment with a step-by-step procedure, or plan.

Your first attempt may come out like Procedure A (opposite page).

Easy enough, right? Well, think about this: If two people read this procedure, would they do the same experiment? Not likely. This plan lacks important details, like how long the ball should be left in the cold or hot water. From what height should you drop the ball? And how will you measure the bounce?

With a good procedure, anyone can repeat the experiment exactly the way you did it. Use this checklist to help get your procedure on track:

* Try to imagine yourself doing the experiment from start to finish.

* Start out with a list of materials you will need. Include amounts or measurements where necessary.

* Test only one independent variable at a time.

* Keep all other variables constant (unchanged) for each trial. That will help you get consistent and reliable results.

* Always include a control, a test subject or condition with which you can compare your results.

* Conduct repeated trials to verify your results.

If you think about these details and rewrite your original procedure, you'll end up with a new and improved plan, something like Procedure B (right).

Be sure to review your procedure for accuracy, completeness, and safety. It would also help to have someone else, like a teacher, parent, or friend, read it to see if he or she can follow the steps. Your reader should be able to imagine doing the experiment. You may have to revise steps or add new ones based on his or her suggestions. For example, you may want to specify the temperatures of the hot and cold water. (You will need a thermometer to do this.)

Can you think of other ways you could improve this experiment?