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Getting Started on a Science Fair Project

by Lois June Wickstrom


The first thing you have to decide about a science fair project is the question you are going to ask. The more you can simplify your question the less work you will have to do in your experiment. It may take a while to ask a really simple question, but the work is worth it!

 The key thing you need to limit in a science fair project is the number of variables. Variables are the things you can change.

If you only have to change one thing to answer your question, you have asked a really good question. Our motto is: Plan to be lazy.

Lots of farmers ask complicated questions like, ``How can I grow the biggest vegetables?'' This may not sound like a complicated question, but think about what you know about growing plants:

  • Do they need light?

  • water?

  • warmth? 

  • dirt to grow in? 

  • fertilizer? 

  • anything else?

Are you sure about your answers? Have you tried growing vegetable seeds in a dark closet (opening it only to water  the seeds.) Have you tried to grow vegetable seeds in a refrigerator where it is both cold and dark? Have you tried to grow vegetable seeds on a paper towel instead of dirt? And what about water?

Does it have to be tap water? What about distilled water? Rain water? Water from a well? Water from a swimming pool? Dirty water from washing dishes? Or your bath? And one look at the fertilizer selection at the farmer's supply store will tell that choosing a fertilizer is not a simple question, either. 

So, what can you do? That's a lot of variables. You'd never finish your science project if you tried to figure out all of them. And besides, you'd never know if you'd tested everything.

There might be a new fertiziler invented tomorrow, or scientists might learn something new about plants that you  could test as well. At this point, you might feel like saying, ``Why bother?''

And you'd be right. That's why you have to plan your experiment carefully -- so it can be simple.

You can ask a simpler question: Do plants need light to grow?

But plants is still too much work. You don't want to have to study all the different kinds of trees, mosses, bushes, flowers, fruits, and vegetables. You want to simplify further -- down to one packet of seeds that you can buy at a garden supply store.

For the sake of this discussion, lets pick Rocket Radishes. 

Next, we have to decide if we are going to study light, or the

Now we can ask, ``Do Rocket Radishes need light to grow?'' The question is simple enough. To answer it, you'll need to try to grow some Rocket Radish seeds in the dark.  But, you may say, the seeds might not be good. They might not grow if they did have light. Then the experiment wouldn't show anything. You're right. That's why scientists use what's called a control.

A control is the same as your experimental project except for one variable. In this case light. Both the control and the experiment have to have enough examples that your answer will mean something.

If you plant one radish in the closet and one on the windowsill, and the one in the closet sprouts, but the one on the sill doesn't, all you have is one sprouted radish seed. It doesn't mean anything. But if you plant ten radishes in the closet and ten radishes on the window sill, and compare the plants, and you see a pattern, then you have enough examples to see what it means.

For example -- all the seeds might sprout, but the 9 of the 10 growing in the closet might die of mildew. If that happened,  you could say that mildew grows better than Rocket Radishes in a closed closet, but not on the window sill. This isn't the answer to your original question, but it as a

Many scientific discoveries have been accidental, like Teflon (r). Others have come about through a new way of looking at old data. For example, researchers knew for decades that mold killed bacteria. If mold got on their petri dishes, where they were growing bacteria for their research they thought their research was ruined. Then one day, researchers decided to look for a way to kill bacteria -- and they thought mold kills bacteria.

That's the origin of penicillin. So don't worry if your research doesn't work out the way you expected. And don't worry if you can't think of a use for what you discovered. Just record what you learn and show it to the judges.

You do want to be sure that you can duplicate your results. If a result only happens once, it's hard to tell what it means. We are trying to avoid hard work. That's why you need to use a control. The control in this case would be Rocket Radish seeds from the same package planted in the same kinds of containers with dirt from the same place, watered with the same amount of water from the same tap. The control plants would be placed on a window ledge (or some other place where they could get light). The experimental Rocket Radish plants would be put on a shelf in the closet, after which you would close the door, except when you are watering or measuring them.

You have to decide how long you are going to let the Rocket Radish plants grow for your experiment. A radish plant can grow all summer long, going through it's entire life cycle and producing seeds for next year's crop. You may not want to take that long for your experiment. You can decide that you will let the plants grow until the radishes in the window are 1'' tall, or for two weeks, or for any other amount of time that you choose.

But for the experiment to show you something, the amount of time has to be reasonable.

You could say that you are going to let the plants grow for one minute. But if neither the window radishes, nor the closet radishes have sprouted in that minute, then your  experiment hasn't answered your question -- ``Do Rocket Radishes need light to grow?''

You don't have to make your experiment quite this simple, but you'll have more meaningful results with less work, once you master the technique of simplifying. For example,  you could decide to water the Rocket Radishes with the seven kinds of water mentioned above, and measure which radishes weigh more. Your question would be ``Which source of water makes radishes weigh more: tap water, well water, rain water, distilled water, swimming pool water, dish water, or bath water?''