This section contains basic information about the process of scientific experimentation and research. It is meant as a general introduction for those who are not familiar with scientific research methods. If you are completely new to research and want to gain some experience, a good way to do that is to follow one of the protocols for studies supplied in Calls for Studies. If you create your own protocol and wish to have feedback and guidance, you may submit it as a Study in Progress to get comments from the community and/or a mentor.
The scientific method is a set of rules and procedures that enable us to test ideas about how the world works, make predictions about events, and create theories. The basic steps are:
1. Observation - observe and describe something that happens.
2. Hypothesis - create a possible explanation for what has been observed.
3. Prediction - use the hypothesis to make a prediction about what will happen in a certain situation.
4. Experiment - test the predictions by experiments or further observations.
5. Conclusions - a statement of what was learned
Let us look at each step in more detail:
The process begins with determining the subject that you will study. The subject is found through observing and describing something that has already happened. This observation may come from our own experience, or from someone else.
Questions to ask include: What is the subject I want to explore? What is important and interesting about this subject? What do I want to discover? What do I already know? State the subject of your study as an observation that you will explore further.
Example: When rocks are placed in water, they sink.
A hypothesis is a possible explanation for what has been observed. In creating a hypothesis, it is helpful to form a question that needs to be answered. The hypothesis is one possible answer to that question.
When coming up with a question, it is important that it be readily answerable, or testable. Answerable questions usually start with the words How, What, When, Who or Which. It is best to avoid questions starting with "Why," because they tend to be too big, vague and unanswerable. For example an "unanswerable" question might be:
Why do rocks sink in water? (It would be very difficult to test this.)
An answerable question would be:
Which solid objects sink in water? (This can be easily tested.)
Once you have a clear, answerable question, you can form your hypothesis, or possible answer. For example, our hypothesis might be:
All solid objects sink in water.
Now we make a prediction about what will happen in a certain situation. In order to make this prediction, we first have to determine what the situation will be. We need to design an experiment.
Designing an experiment
Think about how you can test your hypothesis. Ask yourself, how will I obtain answers to my question? What methods will I use (reading, interviewing, making observations and/or measurements)? What will be the procedure?
Be as specific as you can. How exactly will you gather data? How will you organize it? How will you record it? What tools will you need?
It is important to think about the different variables that could affect the experiment. Variables are any aspects of the experiment that may change and therefore affect the results. You want to test one variable only (for example, solid objects made of different materials), so you want all other variables to stay as constant as possible.
In our example, some variables might be the size of the objects, the temperature of the water, and the size of the water container. So we would want to use objects that are the same size, keep the temperature of the water the same, and test all of the objects in the same container of water.
For our example, we might plan the following experiment:
We will partly fill a small container with water. We will collect three objects, one of stone, one of metal, and one of wood. They must all be the same size, and small enough to place in the container with water in it. We will place each object in the water one at a time, and observe whether it sinks or not. Then we will write down the result.
For more on designing an experiment, see Common Experimental Designs page.
A plan for how an experiment will be conducted is called a protocol. To view some sample protocols, please see the Calls for Studies page.
Making a prediction
Once you have determined how you will conduct your experiment, you can make a prediction about what will happen, based on your hypothesis. A prediction can take the form of an "If . . . then . . ." statement. "If my hypothesis is correct, then such and so will happen." For example:
If all solid objects sink in water, then when I place stone, metal and wooden objects in water, they will all sink.
Now you perform your experiment and record your observations and results. Be very careful to keep all variables constant. Be very observant, and record any observations that may have an impact on the outcome of the experiment.
In our example, we will place our three objects in the water individually, and record our results as follows:
Stone object - sinks
Metal object - sinks
Wood object - floats
We may also note that when we remove each object from the water, they are wet, so they remove a bit of water from the container. Perhaps one of the objects is dusty, so it dirties the water a little before the other objects are placed in. Even small observations like these may be important in some experiments, so be sure to make note of anything that may be significant.
Conclusions are a statement of what was learned through the experimental process. Think about the results and how they relate to the hypothesis. Did the results support the hypothesis? If so, what else would be interesting to study regarding this subject, and how could it be studied? Even if the results were as expected, there are still questions that could be investigated further.
If the results did not support the hypothesis, think about why that may have been the case. Was the hypothesis wrong, or was there some flaw in the experiment? Are there ways that the experiment could be improved? Or, in the process, did you find an even more interesting question that could be studied?
Think again about variables that may have affected the experiment. What could have influenced the outcome? How will you account for those variables? Could further studies be done to test the influence of those variables?
Make note of any observations you made that seemed significant. Did anything happen that surprised you? Was there anything that may be of interest to other people who experiment with this subject?
An ongoing process
The scientific method is not a linear process with a clear beginning and end. It is an ongoing process of inquiry and investigation. Regardless of whether the hypothesis of your experiment was supported or not, your experience and observations add to the body of scientific evidence and help bring greater knowledge to more people.
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