Scientific Method of Solving Problems
There is more than one way to "science, different sources describe the steps of the scientific method in different ways. Some list three steps, some four and some five., and some even as many as seven steps. In the end however, they incorporate the same concepts and principles.
Scientists and those who study science don't sit around with a five-step checklist that they feel obligated to follow. In fact, the process is quite fluid and open to interpretation and modification. One scientist might spend much of his career in the observation stage. Another scientist may never spend a great deal of time designing and running experiments.
This method is also not reserved for highly trained scientists, in fact anyone trying to solve a problem can use it. You have probably used it in your Science class more than once yourself!
William Harris & the How Stuff Works Website
Step 1: Make an observation
Almost all scientific inquiry begins with an observation that piques curiosity or raises a question. For example, when Charles Darwin visited the Galapagos Islands, he observed several species of finches, each uniquely adapted to a very specific habitat. In particular, the beaks of the finches were quite variable and seemed to play important roles in how the birds obtained food. These birds captivated Darwin. He wanted to understand the forces that allowed so many different varieties of finch to coexist successfully in such a small geographic area. His observations caused him to wonder, and his wonderment led him to ask a question that could be tested.
Step 2: Ask a question
The purpose of the question is to narrow the focus of the inquiry, to identify the problem. Coming up with scientific questions isn't difficult and doesn't require training as a scientist. If you've ever been curious about something, if you've ever wanted to know what caused something to happen, then you've probably already asked a question that could launch a scientific investigation.
If we use Darwin as an example again... The question Darwin might have asked after seeing so many different finches was something like this: What caused the diversification of finches on the Galapagos Islands?
Step 3: Formulate a hypothesis
The great thing about a question is that it yearns for an answer, and the next step in the scientific method is to suggest a possible answer in the form of a hypothesis. A hypothesis is often defined as an educated guess because it is almost always informed by what you already know about a topic. For example, if you wanted to study the air-resistance problem stated above, you might already have an intuitive sense that a car shaped like a bird would reduce air resistance more effectively than a car shaped like a box. You could use that intuition to help formulate your hypothesis.
A hypothesis is stated as an "if … then" statement. In making such a statement, scientists engage in deductive reasoning, which is the opposite of inductive reasoning. Deduction requires movement in logic from the general to the specific. Here's an example: If a car's body profile is related to the amount of air resistance it produces (general statement), then a car designed like the body of a bird will be more aerodynamic and reduce air resistance more than a car designed like a box (specific statement).
Notice that there are two important qualities about a hypothesis expressed as an "if … then" statement. First, it is testable; an experiment could be set up to test if the statement it true based on the statement. Second, it is believed to be false; an experiment could be devised that might reveal that such an idea is not true. If these two qualities are not met, then the question being asked cannot be addressed using the scientific method.
Step 4: Conduct an experiment
Many people think of an experiment as something that takes place in a lab. While this can be true, experiments don't have to involve laboratory workbenches, Bunsen burners or test tubes. They do, have to be set up to test a specific hypothesis and they must be controlled. Controlling an experiment means controlling all of the variables so that only a single variable is studied. The independent variable is the one that's controlled and manipulated by the experimenter, whereas the dependent variable is not. As the independent variable is manipulated, the dependent variable is measured for variation. In our car example, the independent variable is the shape of the car's body. The dependent variable -- what we measure as the effect of the car's profile -- could be speed, gas mileage or a direct measure of the amount of air pressure exerted on the car.
Controlling an experiment also means setting it up so it has a control group and an experimental group. The control group allows the experimenter to compare his test results against a baseline measurement so he can feel confident that those results are not due to chance. For example, in the Pasteur experiment described earlier, what would have happened if Pasteur used only a curved-neck flask? Would he have known for sure that the lack of bacteria growth in the flask was because of its design? No, he needed to be able to compare the results of his experimental group against a control group. Pasteur's control was the flask with the straight neck.
Now consider our air-resistance example. If we wanted to run this experiment, we would need at least two cars -- one with a streamlined, birdlike shape and another shaped like a box. The former would be the experimental group, the latter the control. All other variables -- the weight of the cars, the tires, even the paint on the cars -- should be identical. Even the track and the conditions on the track should be controlled as much as possible.
|Step 5: Analyze data and draw a conclusion|
|During an experiment, scientists collect both quite a lot of data. Buried in that information, hopefully, is evidence to support or reject the hypothesis. The amount of analysis required to come to a satisfactory conclusion can vary tremendously. Because Pasteur's experiment relied on qualitative observations about the appearance of the broth, his analysis was fairly straightforward. Sometimes, sophisticated statistical tools have to be used to analyze data. Either way, the ultimate goal is to prove or disprove the hypothesis and, in doing so, answer the original question.|
Adapted from How Stuff Works: "How the Scientific Method Works"
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CyberBullying is a hot topic right now, and is one that I consider to be of extreme importance for the well being of my students. As a parent and teacher, bullying is an issue that I take very seriously and am always looking for new resources. Here are a few of the best I have reviewed lately:
- Common Sense
- STOP CyberBullying
- CyberBully Guide
- Make a Difference for Kids
- Cyberbully Research Center
Thanks also to Mrs. Baranowski's Technology Class from the Colonial Academy for suggesting a few of the resources above! Keep up the great work!
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