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What is the Scientific Method?

The scientific method is a systematic outline for gathering information by observation and experimentation. The basic steps of the scientific method are:

Step 1: Observation
Step 2: Question
Step 3: Hypothesis
Step 4: Experiment
Step 5: Results
Step 6: Conclusion

Let's take an example and walk through each step.

Step 1: Observation
Let's begin with a simple observation made while working in your garden. You especially like growing zucchini and you notice that some of your zucchini plants grow much larger zucchinis than others.

Step 2: Question
In this step you pose a question to be answered and/or identify the problem you wish to solve. So, you're curious about the size differential between your zucchini plants. What factors might affect the size of a plant? Factors to consider would be the amount of water or sunlight each plant receives, or perhaps the type of soil in which each plant is grown.

For the purpose a good experiment, you would want to select only one variable to test. In this case, let's select the water variable. A good question would therefore be "Does the amount of water a zucchini plant receives affect the size of the zucchini?"

Step 3: Hypothesis
In this step you formulate a tentative answer, or hypothesis. In it's simplest form, a hypothesis can be considered similar to a prediction or even to an 'educated guess'. Based on your knowledge of growing zucchini plants (the 'educated' part of the 'educated guess'), what do you "guess" will be the result of your experiment? Do you think that more water will increase or decrease the size of your zucchini plant?

You know from your experience in gardening that zucchini plants require water to survive and grow. You've also noticed that the plants that get more water thrive and grow larger than those plants that don't get as much water. In this example, therefore, we will hypothesize that the more water a zucchini plant receives, the larger its zucchini will grow.

Step 4: Experiment
Gathering data is the next step in the scientific method. To gather this data, you must design an experiment that will test the hypothesis you made in Step 3. Let's say that you will use twelve plants in your test. You can split the plants into three groups - four plants per group - to help ensure that your results are conclusive.

You must be careful to control all the variables in the experiment so that only the one variable - amount of water - will be different for each group of test plants. This means that you will need to ensure that the other variables - amount of sunlight, soil type, and plant type - are all the same.

Step 5: Results
You test your hypothesis by running your experiments and making notes of the results. In this example, you grow three sets of four zucchini plants each, making sure that each sample is composed of plants of the same type, grown in the same soil and given the same amount of sunlight.

Each sample, however, is given water in differing amounts. One sample receives that usual, or recommended, amount of water for a zucchini plant. This sample would be your "control" sample. Another sample then receives a greater amount of water than the control sample, and the third sample would receive a lesser amount of water than the control sample.

A key element in executing a scientific experiment is to keep good records. Then, at the end of the experiment you can use these results to analyze your data.

Step 6: Conclusion
After your experiment is completed, you will make a conclusion based on the data gathered. Was your hypothesis right or wrong? Did the plants that received more water actually grow larger zucchinis?

At this point you have two options for your conclusion. Firstly, you can reject your hypothesis. If the sample that received more water didn't produce larger zucchinis than the other samples - with all other variables being the same - then you could reject your hypothesis.

Your other choice is to NOT reject the hypothesis. Note that this is entirely different than "proving" your hypothesis. You cannot prove any hypothesis with only one experiment. There may have been other variables of which you were not aware - something on the microscopic level, or something that occurred when you were not watching the plants - say bird or vermin infestation that occurred at night and left no outward traces. What a scientist CAN say at this point would be that the results support the hypothesis. If your results support the hypothesis, then you can use your data to form a theory. More testing would then be needed before this theory might become accepted as fact.

Step 7?
Sometimes a seventh step is included, in which the scientist modifies her theory. For example, if the results of your experiment didn't match up with your hypothesis, try to determine why your original hypothesis was incorrect. Come up with a new hypothesis and run another experiment.

When you use the scientific method, it is not only acceptable to be wrong but it sometimes contributes more to the bank of scientific knowledge if you are wrong! What is important is that the research was conducted in a logical and scientific manner, and that follow-up is conducted on any conclusions reached. Each new experiment can contribute not only new data but, perhaps more importantly, new questions for the scientific community to examine.

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