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Six Steps of the Scientific Method

Learn What Makes Each Stage Important

ThoughtCo. / Hugo Lin 

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• Ph.D., Biomedical Sciences, University of Tennessee at Knoxville
• B.A., Physics and Mathematics, Hastings College

The scientific method is a systematic way of learning about the world around us. The key difference between the scientific method and other ways of acquiring knowledge is that, when using the scientific method, we make hypotheses and then test them with an experiment.

Anyone can use the scientific method to acquire knowledge by asking questions and then working to find the answers to those questions. Below are the six steps involved in the scientific method and variables you may encounter when working with this method.

The Six Steps

The number of steps in the scientific method can vary from one description to another (which mainly happens when data and analysis are separated into separate steps), however, below is a fairly standard list of the six steps you'll likely be 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, you might conduct much of your research online. As you read articles and papers online, ensure you scroll to the bottom of the text to check the author's 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'll be to conduct your investigation.
• Hypothesis Propose a hypothesis . This is a sort of educated guess about what you expect your research to reveal. A hypothesis 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. The null hypothesis or the no-difference hypothesis is one type of hypothesis that's easy to test because it assumes changing a variable will not affect the outcome. In reality, you probably expect a change, but rejecting a hypothesis may be more useful than accepting one.
• Experiment Design and 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 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's no right or wrong outcome to an experiment, so either result is fine. Accepting a hypothesis doesn't 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. You can compile your results into a lab report or formally submit them 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.

When Are There Seven Steps?

Some teach the scientific method with seven steps instead of six. In the seven-step model, the first step is to make observations. Even if you don't make observations formally, you should think about prior experiences with a subject 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're 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 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 you missed.
• Independent Variable:  This is the variable you control.
• Dependent Variable:  This is the variable you measure. It's called the dependent variable because it  depends  on the independent variable.
• Null Hypothesis Examples
• Scientific Method Flow Chart
• Random Error vs. Systematic Error
• What Is an Experimental Constant?
• Scientific Variable
• What Is a Hypothesis? (Science)
• What Are the Elements of a Good Hypothesis?
• What Are Examples of a Hypothesis?
• What Is a Testable Hypothesis?
• Scientific Hypothesis Examples
• Scientific Method Vocabulary Terms
• Understanding Simple vs Controlled Experiments
• The Role of a Controlled Variable in an Experiment
• What Is the Difference Between a Control Variable and Control Group?
• What Is a Controlled Experiment?
• DRY MIX Experiment Variables Acronym

How to Conduct Experiments Using the Scientific Method

Introduction: How to Conduct Experiments Using the Scientific Method

Experiments are performed all around us everyday. Whether they're done to find out if a cancer curing medication works or to find out how fast water evaporates at certain temperatures, experiments are constantly performed. However, what separates a simple experiment from a professionally done experiment is the use of the Scientific Method. The Scientific Method is a series of organized steps to which an experiment is done. The Scientific Method helps you plan, predict, research, conclude and maybe even publish your findings. The Scientific Method will make your experiment more organized, easy to interpret and learn from. In this Instructable, I will help guide you through each step using a sample experiment. You will also learn the significance of each step as I break the Scientific Method down.

The steps to the Scientific Method are:

1) Pose a Testable Question.

2) Conduct Background Research.

3) State your Hypothesis .

4) Design Experiment .

5) Perform your Experiment .

6) Collect Data .

7) Draw Conclusions .

8) Publish Findings (optional).

Step 1: Understand the Sample Experiment

Our sample experiment is going to be the rate of sugar cubes dissolving in water at different temperatures. Basically, I will drop sugar cubes into cups of water with different temperatures and time how long it takes the sugar cubes to "disappear" (dissolve).

Step 2: Pose a Testable Question

The Testable Question is the question that the experiment is based on. Every experiment is performed because someone questions or is curious about something. So, all the T estable Question really does, is pose that burning question.

In the sample experiment, our Testable Question is:

Does water temperature affect the rate at which sugar cubes dissolve?

Step 3: Research the Topic

Researching your topic is very important. It helps you predict an outcome (Hypothesis) and helps you to better understand the subject.

Your research should include, information about prior experiments done that are the same or similar to yours, information about things you are using in your experiment (chemicals, tools, etc.), definitions of words that you don't know that are relevant to your experiment, etc.

Your research doesn't need to be organized in any particular fashion. Some ways to organize your information are bullet points, charts and graphs (t-charts, spreadsheets, bar graphs, line graphs, etc.), list of words and their respective definitions, etc.

Step 4: State a Hypothesis

The Hypothesis is a prediction, based on prior research, on the outcome of the experiment. Think of the Hypothesis as an educated estimate.

Your Hypothesis will predict your opinion on the outcome of the experiment. If research points one way, and you predict that your experiment will go another way, that's totally fine. That's the point of doing the experiment. To see if your Hypothesis is right or wrong.

A Hypothesis is usually stated using a 'if and then' statement. Your sentence will sound something like, If I drink water, then I will feel hydrated.

In the sample experiment, the Hypothesis can be:

If you increase water temperature, then the rate at which a sugar cube dissolves is increased.

Remember, the hypothesis can be any prediction of the outcome of the experiment you are conducting. So, again, this doesn't have to be your hypothesis.

Step 5: Design Your Experiment

There are five main things to cover in the design step. Those five things are:

1) Make a list of parts, materials and tools needed for your experiment.

2) Declare your control.

3) Declare your independent variable.

4) Declare your dependent variable.

5) Describe how you will perform your experiment.

Make a List of Parts, Materials and Tools Needed for your Experiment

For the sample experiment I will need:

• Two clear plastic cups filled with half a cup of water
• A thermometer
• Two sugar cubes
• Distilled water
• A stopwatch
• A measuring cup
• Two microwaveable bowls

Declare your Control Variable

The control variable is the normal scenario.

For the sample experiment, the control variable is:

• A cup of water that is room temperature (seventy two degrees Fahrenheit).

Declare your Independent Variable The independent variable is the one variable you change that makes the scenario different than normal conditions (control).

For the sample experiment, the independent variable is:

• Increasing the water temperature to about ninety five degrees Fahrenheit. This is the independent variable because the control, or normal scenario is about seventy two degrees Fahrenheit.

Please note that you can only change one variable per experiment. If more than one variable is made different than the control, your experiment is invalid and the information could be considered wrong.

Declare your Dependent Variable

The dependent variable is the way you will measure the results of the experiment.

For the sample experiment, the dependent variable is:

• How long it takes for the sugar cube to completely "disappear" (dissolve).

Describe how the Experiment will be Performed

Your description should be written so that if anyone were to read it, that person would be able to conduct the experiment just the way you did it.

For the sample experiment, the description should go like this:

• In this experiment, I filled two cups with half a cup of distilled water. One cup was measured at approximately seventy five degrees Fahrenheit and the other cup was measured at ninety five degrees Fahrenheit. I dropped a sugar cube in the first cup and started the stopwatch exactly at the same time when the sugar cube touched the water. I repeated the process one more time with the second cup. After the sugar cube completely disappeared, I stopped the stopwatch and recorded my results. I repeated the process one more time with the second cup.

Step 6: Perform the Experiment

All you have to do in this step is perform the experiment exactly as you described in the description in the last step.

Step 7: Collect Data

When you finish timing the first cup, write down your results. Repeat that with the second cup.

Your data collection at this point, doesn't need to be fancy. All this step does is ensure that you know what the data is so you could make it fancy and presentable in the next step with graphs and charts.

For the sample experiment, the data was:

• In the first cup (seventy five degrees Fahrenheit), the sugar cube dissolved in
• In the second cup (ninety five degrees Fahrenheit), the sugar cube dissolved in twenty four minutes and thirty seconds.

Step 8: Conclusions

When you finish collecting your Data, you should now conclude with an analysis of your experiment.

Your analysis should include:

1) Charts and graphs displaying results

2) A sentence/paragraph that states if you accept or reject your hypothesis

3) A summary recapping your experiment (optional)

Charts and Graphs

For the sample experiment, I would recommend using a bar graph.

Rejecting/Accepting Hypothesis

For the sample experiment, your paragraph should go like this:

• In my experiment, my hypothesis was rejected because the sugar cube dissolved into seventy five degree Fahrenheit water dissolved in less time than the ninety five degree Fahrenheit water.

Step 9: Publishing Findings (optional)

If your experiment was groundbreaking, really interesting or anything along those lines, you might want to consider publishing in a science magazine or journal.