- A, C, B, D, E
- B, C, A, E, D
- C, D, E, B, A
- B, A, C, E, D
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The scientific method is a systematic way of learning about the world around us and answering questions. The key difference between the scientific method and other ways of acquiring knowledge are forming a hypothesis and then testing it with an experiment.
The number of steps can vary from one description to another (which mainly happens when data and analysis are separated into separate steps), however, this is a fairly standard list of the six scientific method steps that you are expected to know for any science class:
- Purpose/Question
Ask a question. - Research
Conduct background research. Write down your sources so you can cite your references. In the modern era, a lot of your research may be conducted online. Scroll to the bottom of articles to check the references. Even if you can't access the full text of a published article, you can usually view the abstract to see the summary of other experiments. Interview experts on a topic. The more you know about a subject, the easier it will be to conduct your investigation. - Hypothesis
Propose a hypothesis. This is a sort of educated guess about what you expect. It is a statement used to predict the outcome of an experiment. Usually, a hypothesis is written in terms of cause and effect. Alternatively, it may describe the relationship between two phenomena. One type of hypothesis is the null hypothesis or the no-difference hypothesis. This is an easy type of hypothesis to test because it assumes changing a variable will have no effect on the outcome. In reality, you probably expect a change but rejecting a hypothesis may be more useful than accepting one. - Experiment
Design and perform an experiment to test your hypothesis. An experiment has an independent and dependent variable. You change or control the independent variable and record the effect it has on the dependent variable. It's important to change only one variable for an experiment rather than try to combine the effects of variables in an experiment. For example, if you want to test the effects of light intensity and fertilizer concentration on the growth rate of a plant, you're really looking at two separate experiments. - Data/Analysis
Record observations and analyze the meaning of the data. Often, you'll prepare a table or graph of the data. Don't throw out data points you think are bad or that don't support your predictions. Some of the most incredible discoveries in science were made because the data looked wrong! Once you have the data, you may need to perform a mathematical analysis to support or refute your hypothesis. - Conclusion
Conclude whether to accept or reject your hypothesis. There is no right or wrong outcome to an experiment, so either result is fine. Accepting a hypothesis does not necessarily mean it's correct! Sometimes repeating an experiment may give a different result. In other cases, a hypothesis may predict an outcome, yet you might draw an incorrect conclusion. Communicate your results. The results may be compiled into a lab report or formally submitted as a paper. Whether you accept or reject the hypothesis, you likely learned something about the subject and may wish to revise the original hypothesis or form a new one for a future experiment.
Sometimes the scientific method is taught with seven steps instead of six. In this model, the first step of the scientific method is to make observations. Really, even if you don't make observations formally, you think about prior experiences with a subject in order to ask a question or solve a problem.
Formal observations are a type of brainstorming that can help you find an idea and form a hypothesis. Observe your subject and record everything about it. Include colors, timing, sounds, temperatures, changes, behavior, and anything that strikes you as interesting or significant.
When you design an experiment, you are controlling and measuring variables. There are three types of variables:
- Controlled Variables: You can have as many controlled variables as you like. These are parts of the experiment that you try to keep constant throughout an experiment so that they won't interfere with your test. Writing down controlled variables is a good idea because it helps make your experiment reproducible, which is important in science! If you have trouble duplicating results from one experiment to another, there may be a controlled variable that you missed.
- Independent Variable: This is the variable you control.
- Dependent Variable: This is the variable you measure. It is called the dependent variable because it depends on the independent variable.
The scientific method is a process for experimentation that is used to explore observations and answer questions.
Do all scientists follow the scientific method exactly? No. Some areas of science can be more easily tested than others. For example, scientists studying how stars change as they age or how dinosaurs digested their food cannot fast-forward a star's life by a million years or run medical exams on feeding dinosaurs to test their hypotheses. When direct experimentation is not possible, scientists modify the scientific method. But even when modified, the goal (and many of the steps) remains the same: to discover cause and effect relationships by asking questions, carefully gathering and examining the evidence, and seeing if all the available information can be combined into a logical answer. New information or thinking might also cause a scientist to back up and repeat steps at any point during the process. Understanding the steps of the scientific method will help you focus your scientific question and work through your observations and data to answer the question as well as possible.
The interactive diagram below may help you understand the scientific method and how it is applied to an experiment. You can click on parts of the diagram to learn more. Use the "return to top" button
The scientific method starts when you ask a question about something that you observe: How, What, When, Who, Which, Why, or Where?
For a science fair project some teachers require that the question be something you can measure, preferably with a number.
For detailed help with this step, use these resources:
- Your Question
- Laboratory Notebook
A hypothesis is an educated guess about how things work. It is an attempt to answer your question with an explanation that can be tested. A good hypothesis allows you to then make a prediction:
"If _____[I do this] _____, then _____[this]_____ will happen."
State both your hypothesis and the resulting prediction you will be testing. Predictions must be easy to measure.
For detailed help with this step, use these resources:
Your experiment tests whether your prediction is accurate and thus your hypothesis is supported or not. It is important for your experiment to be a fair test. You conduct a fair test by making sure that you change only one factor at a time while keeping all other conditions the same.
You should also repeat your experiments several times to make sure that the first results weren't just an accident.
For detailed help with this step, use these resources:
- Experimental Procedure
- Materials List
- Conducting an Experiment
Once your experiment is complete, you collect your measurements and analyze them to see if they support your hypothesis or not.
Scientists often find that their predictions were not accurate and their hypothesis was not supported, and in such cases they will communicate the results of their experiment and then go back and construct a new hypothesis and prediction based on the information they learned during their experiment. This starts much of the process of the scientific method over again. Even if they find that their hypothesis was supported, they may want to test it again in a new way.
For detailed help with this step, use these resources:
- Data Analysis & Graphs
- Conclusions
To complete your science fair project you will communicate your results to others in a final report and/or a display board. Professional scientists do almost exactly the same thing by publishing their final report in a scientific journal or by presenting their results on a poster or during a talk at a scientific meeting. In a science fair, judges are interested in your findings regardless of whether or not they support your original hypothesis.
For detailed help with this step, use these resources:
- Final Report
- Abstract
- Display Board
- Science Fair Judging
Frequently Asked Questions
What are the six steps of the scientific method?
The six steps of the scientific method include: 1) asking a question about something you observe, 2) doing background research to learn what is already known about the topic, 3) constructing a hypothesis, 4) experimenting to test the hypothesis, 5) analyzing the data from the experiment and drawing conclusions, and 6) communicating the results to others.
What is a scientific method example?
A simple example of the scientific method is:
- Ask a Question: Why does Greenland look so large on a map?
- Background Research: Learn that Greenland is a quarter the size of the United States in land mass. Also learn that Mercator projection maps are made by transferring the images from a sphere to a sheet of paper wrapped around the sphere in a cylinder.
- Hypothesis: If I make a Mercator projection map, then the items in the middle of the map will look their true size and the items at the poles will look larger than they really are.
- Experiment: Use a sphere with 1-inch by 1-inch squares at each pole and the equator to make a Mercator projection map. Measure the squares on the Mercator projection map.
- Analyze Data and Make Conclusions: The middle-of-the-map squares average 1 inch per side while the squares at the poles average 3 inches per side. In conclusion, the projection process used to make Mercator projection maps creates distortion at the poles, but not at the equator. This is why Greenland, which is close to the North Pole, looks larger than it is.
- Communicate: Make a video, write a report, or give a presentation to educate others about the experiment.
Who invented the scientific method?
The scientific method was not invented by any one person, but is the outcome of centuries of debate about how best to find out how the natural world works. The ancient Greek philosopher Aristotle was among the first known people to promote that observation and reasoning must be applied to figure out how nature works. The Arab Muslim mathematician and scientist Hasan Ibn al-Haytham (known in the western world as Alhazen) is often cited as the first person to write about the importance of experimentation. Since then, a large number of scientists have written about how science should ideally be conducted and contributed to our modern understanding of the scientific method. Those scientists include Roger Bacon, Thomas Aquinas, Galileo Galilei, Francis Bacon, Isaac Newton, John Hume, and John Stuart Mill. Scientists today continue to evolve and refine the scientific method as they explore new techniques and new areas of science.
Do scientists actually use the scientific method?
Scientists do use the scientific method, but not always exactly as laid out in the organized steps taught in the classroom. Just like a chef might make a few changes to a recipe because of the ingredients at hand, a scientist may modify the scientific method by skipping steps, jumping back and forth between steps, or repeating a subset of the steps because he or she is dealing with imperfect real-world conditions. But scientists always strive to keep to the core principles of the scientific method by using observations, experiments, and data to support or reject explanations of how a phenomenon works. While experimenting is considered the best way to test explanations, there are areas of science, like astronomy, where this is not always possible.
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