The Scientific Methods

The SCIENTIFIC METHOD is the logical way in which a scientist goes about trying to solve a problem. A student needs to understand the scientific method, and the words that are used to describe the process. The actual descriptions of the steps of the scientific method will vary from text to text, but the underlying process remains the same. The steps of the scientific method are shown below:

1. State the problem.
2. Collect observations.
3. Form a hypothesis.
4. Test the hypothesis.


Now, let us review a real life example of how you might use the scientific method. Suppose you notice an area in your front lawn where the grass is not growing correctly. The rest of your lawn has thick, green grass, but this one area has very sparse grass. This, then, is your problem.

1. State the problem.

"Grass won't grow in that area of my lawn!"

You would then go outside and look at that area. What makes that area different from the areas where the lawn is growing nicely? Does one area get more or less sun? What is the soil like? Compare as many likely factors that you can think of.

2. Collect observations.

"The sparse area is surrounded by several evergreen trees, which drop needles and block much of the sunlight. The soil appears just as rich as the soil in other areas, but the pH is lower. All areas seem to be getting similar amounts of water. The temperature in the shaded area is lower than the areas that are not shaded."

Based on the information that you gathered, and your knowledge of Biology, you are ready to form a hypothesis. Remember, a hypothesis is an educated guess. It is only your background knowledge in this subject that separates a true hypothesis from what would merely be a guess. Now, considering the observations you made, you might decide that pH of the soil in the sparse area is the problem. You form a hypothesis and put it in what is called "if . . . then" format.

3. Form a hypothesis.

"If the pH of the soil was higher, then my grass would grow properly."

Now you want to design an experiment that can be used to test your hypothesis. It is important that your experiment be controlled, that you keep all conditions between groups the same, except for that condition which you are testing. It is also important that you conduct your experiment on several different samples, so that your results may prove conclusive.

4. Test the hypothesis.

"I took 200 small pots and used them to grow 200 samples of grass. I split the 200 pots into 5 groups of 40, and I adjusted the pH of the soil with calcium oxide (lime) until the five groups had pH readings of; 3,5,7,9, and 11 respectively. In all of the samples I used the same amount and type of soil and the same type and number of grass seeds. Each sample was kept in the same room with identical conditions as far as light, temperature and water."