Chemistry is an experimental science. To learn new things we need to be curious about the world around us. Once something has our attention, we begin to ask questions. We may ask why something is the way it is, how something happened, or even what something is. After we have a question we want to explore, we create an experiment to help us answer our question. Questioning and experimentation are the heart of the scientific method.
There is no formal definition for the scientific method. However, the scientific method has a long history, birthed during the scientific revolution. In the 1700s, Francis Bacon suggested that observation is the best way to learn about our world. Robert Boyle expanded Bacon's idea. Boyle argued that the best form of observation is experimentation. From the 1700s to today, scientists have used observation and experimentation. Because it has such a long history, we can lay out the steps a scientist takes.
Steps in the Scientific Method:
Ask a Question:
The first step is to figure out what you want to know. Your question should be about something in the physical world. Our world is made up of matter, atoms, and molecules. We are continually discovering new applications. There is so much to explore! But, the scientific method can only answer questions about what is observable and measurable (qualitative and quantitative).
Research the Topic:
After you have formulated your question, your next step is to research your topic. The goal of your research is to learn what other scientists have already done and what scientific knowledge already exists. Early on in school many of the questions you ask will already have answers. That's okay! Your goal is to learn. As you progress further in science you may be asking questions that no one has answered. In this case, the goal of your research is to help you understand your topic of study. Even experts cannot keep up to date with all the new research. It's important to know what other scientists have done. You can use their conclusions to help you make predictions.
Make a Hypothesis:
Your hypothesis is a statement about what you expect your experiment to show. A hypothesis can be very general or very specific. However, it must be falsifiable. Many people worry about their hypothesis being false. Do not worry! If your hypothesis is false, it means that you learned something that you were not expecting. Many famous scientists have had their hypotheses disproven. Sometimes it is as helpful to learn what is wrong as what is right.
Make a Prediction based on your Research:
Your prediction is the reasoning behind your hypothesis. Your prediction explains why you expect your hypothesis to be correct. Your prediction is based on the research you have done.
Design and Conduct an Experiment:
Finally, we arrive at the most fun part! Remember that you must design your experiment to answer your question. To do this your experiment needs to have three components:
- The independent variable is what you are changing or manipulating.
- The dependent variable is what responds to your manipulation. The change in the dependent variable is what you are measuring.
- The control is something that you keep the same. You keep the control the same to show that it actually is your manipulation that is causing the change.
Analyze the Experimental Data:
After you have completed your experiment, you have to analyze your data. You are looking for any patterns or trends. Sometimes your trends will be qualitative. For example, you noticed a physical change. Most often, your trends will be quantitative. When you advance further in chemistry, you will use statistics to show quantitative trends.
Draw Conclusions:
Once you have analyzed your data, you are ready to draw conclusions. There are three possible conclusions:
- Your hypothesis and prediction were correct.
- Your hypothesis and prediction were incorrect.
- Your experiment was inconclusive. An inconclusive result is often caused by a flaw in the experimental design.
Science in the Real World: Professional Scientists and The Peer Review Process
After completing an experiment, professional scientists will try to publish their work. For a scientist to get their research published, it must be peer-reviewed. In a peer-review, other scientists from the same field read and comment on the article. The reviewers look at the quality of the writing, adherence to the scientific method, the quality of the experimental design, and the importance of the results. The scientist has the opportunity to make changes based on the reviewers' comments. The scientist then resubmits the paper to the journal. The journal editors then decide if the paper is important enough to publish. Many of the most prestigious journals will publish less than 10% of the articles they receive. These journals are necessary to publish scientific papers in because they push the scientific field farther and allow for new discoveries.
