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Science and Scientific Method

Science refers to a system of acquiring
knowledge, the effort to discover, and increase human understanding of how the physical world work.

This system uses observation and experimentation to describe
and explain natural phenomena.

The word science often describes any systematic field of
study or the knowledge gained from it.(Biology, physics, chemistry..)

A scientist a person who uses observation, experimentation and theory to learn about a subject.

The scientific method is a process for experimentation that is used to explore observations and answer questions. Scientists use the scientific method to search for cause and effect relationships in nature.

The scientific method is a way to ask and answer scientific questions by making observations and doing experiments.
It is important for your experiment to be a fair test.

A "fair test" occurs when you change only one factor (variable) and keep all other conditions the same.
Here are the steps of a scientific method:

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."

If you conduct your experiment carefully, you will probably find differences between the groups of grass that you grew. If don't see anything that leads you to believe that the higher pH would cause growth problems in your lawn, then you may reject your original hypothesis and form a new one, maybe one that is based on the difference in sunlight. If your experiment supports your hypothesis, then you may be on to something, but more testing would be required before you could say for sure.