OK, so an experiment is an observation where you do something to test an idea. Instead of just using your senses, you actively cause something to happen. Once you really think about it, you use experiments all the time. Consider the following example:
That seems perfectly reasonable, but how does that relate to experiments and the process of science? Lets look at it again.
- You turn on the television, and nothing happens.
You have a problem to solve. - You try changing channels.
You formed the hypothesis (What is a Hypothesis?) that the channel you selected might be off the air. You tested that by performing an experiment. You changed one variable (the channel) by selecting a different channel. There was still no image or sound, so it does not support your hypothesis. - You check to see if it is plugged in.
You formed another hypothesis that the television might not have any power. You tested that with an observation, not an experiment, by looking to see if the television was plugged in. You might have also performed an experiment by plugging a different device into the outlet, to be sure that the outlet has power. (Just looking at the plug is an observation. Unplugging the television, and plugging in another device to test the outlet is an experiment. The variable was the device that was plugged into the outlet.) You found that television was plugged in and that the outlet has power, so your observation and experiment do not support this new hypothesis. - You try a television in a different room.
You formed the hypothesis that the problem might be with the television itself. You tested that by turning on a different television. You found that the other television is not working either, so your experiment does not support this hypothesis. Because you had changed several variables (different television, cable connection in a different room, different power supply), if that television had worked, you would have needed to perform additional experiments to find out which variable was responsible. You could have changed only one variable by disconnecting both televisions, and connecting the second television in the room where the original television was. - You call your neighbor, to ask if their television is working.
You form the hypothesis that maybe you forgot to pay the cable bill, and have been disconnected. You test that by going to your neighbor's house, and asking to turn on their television to see if it is working properly. You find out that their televisions don't work either, so this experiment does not support the hypothesis. Again, you changed several variables. - You call the cable company.
You form the hypothesis that there may be a problem at the cable company. You test that by calling to ask about the problem, and find out that there is an outage in your area. This is not an experiment because you did not change anything. It is an observation, but it did support your hypothesis.
By simply troubleshooting a problem with your television, you have formed a hypothesis, tested it with an experiment, decided if the experiment supported or did not support your hypothesis, formed a new hypothesis, and continued the process until you found the problem. You use the same process every day. Try breaking down each of the following the same way we looked at the television problem.
- You are talking to a friend on your cell phone, and have a bad connection. You move to a different room, but still hear static. You go outside, and still hear static. You hang up, and call your friend back. This time you have a better connection.
- You are making a pot of chili. You followed the recipe, but when you taste it, you think something is missing. You put a spoon of chili into a bowl, and add some salt. You compare the taste with the pot of chili, and decide that the salt does not help. You do the same thing with some chili powder, and this time the flavor is improved. You repeat the process with the spice cumin, and again, the flavor is improved. You repeat the process again with some hot sauce, but the flavor is not improved. You add chili powder and cumin to the pot of chili, and are pleased with the flavor.
- Your dog is sitting there, looking at you and whining. You throw her favorite toy. She plays with it for a while, but then comes back to sit and whine. You open the back door to let her out. She runs outside, chases a squirrel, and comes back in. Then she comes back to sit and whine. You feed her, and she delighted gobbles up the food. Then she comes back to sit and whine. You throw her toy again, and she plays with it again. Then she comes back to sit and while. You decide that your dog has trained you to do things for her whenever she sits and whines at you.
It is important to understand that experiments are part of your daily life. From science fair projects and lab work, it is easy to get the impression that for every experiment you are required to start by writing down a clearly stated hypothesis in the proper format, and then follow the Scientific Method precisely step by step, and wind up by gluing everything onto a special, science fair project board with the required number graphs and photographs.
Learning the step by step process of the Scientific Method is important. It helps us learn to think more scientifically in our experiments, but most scientists will tell you that they often do not go through the entire process, step by step. Instead, they often tackle scientific problems in much the same way you would deal with a television that does not work.