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The Scientific Method

The Scientific Method


A science project is an investigation using the scientific method to discover the answer to a scientific problem.  Before starting your project, you will need to understand the scientific method.  The scientific method is the ¡§tool¡¨ that scientists use to find the answers to questions.  It is the process of thinking through the possible solutions to a problem and testing each possibility to find the best solution.  The scientific method involves the following steps:

  • Doing research
  • Identify the problem (in question form)
  • State the hypothesis
  • Conduct an experiment
  • Observe and record your data
  • Draw a conclusion 

 

Doing Research

Research is the process of collecting information from your own experiences, knowledgeable sources, and data from exploratory experiments.  Your first research is used to select a project topic.  This is called topic research.  For example, you observe a black growth on bread slices and wonder how it got there.  Because of this experience, you decide to learn more about mold growth.  Your topic will be about fungal reproduction.

 

After you have selected a topic, you begin what is called project research.  This is research to help you understand the topic, express a problem, propose a hypothesis, and design one or more project experiments- experiments designed to test the hypothesis.  Investigate what others have already learned about your question.  The result of this experiment and other research give you the needed information for the next step ¡V identifying the problem.

¡P      Do use as many references from printed sources ¡V books, journals, magazines, and newspapers ¡V as well as electronic resources ¡V computer software and online services.

¡P      Do gather information from professionals ¡V instructors, librarians, scientists, such as physicians and veterinarians.

¡P      Do perform other exploratory experiments related to your topic.

 

Identify the Problem

The problem is the scientific question that needs to be solved.  It is best expressed as an ¡§open-ended¡¦ question, which is a question that is answered with a statement, not just yes or no. 

 

These questions may begin with the word how, why, or when but shouldn¡¦t begin with the word does or is.

¡P      Do limit your problem

¡P      Do choose a problem that can be solved by performing an experiment.

 

State a Hypothesis

A hypothesis is a possible answer to a scientific question, based on knowledge and research.  While the hypothesis is a single statement, it is the key to a successful project.  All of your project research is done with the goal of expressing a problem, proposing an answer to it (the hypothesis), and designing project experimentation.  Then all of your project experimenting will be performed to test the hypothesis.  The hypothesis should make a claim about how two factors relate. 

 

 

 

 

Here is one example of a hypothesis:

¡§I believe that bread mold does not need light for reproduction on white bread.  I base my hypothesis on these facts: (1) organisms with chlorophyll need light to survive.  Molds do not have chlorophyll and (2) in my exploratory experiment, bread mold grew on white bread kept in a dark bread box.¡¨

  

¡P      Do state facts from past experiences or observations on which you base your hypothesis.

¡P      Do write down your hypothesis before beginning the project experimentation.

¡P      Don¡¦t change your hypothesis even if experimentation does not support it.  If time permits, repeat or redesign the experiment to confirm your results.

 

Conduct an Experiment

Project experimentation is the process of testing a hypothesis.  The things that have an effect on the experiment are called variables.  There are three kinds of variables that you need to identify in your experiment: manipulated, responding, and controlled.  The manipulated variable is the variable that you purposely manipulate (change).  The responding variable is the variable that is being observed, which changes in response to the manipulated variable.  The variables that are not changed are called controlled variables.

 

A controlled experiment is a test in which you are only changing the manipulated variable on purpose. All other variables are held constant.

 

Scientists run experiments more than once to verify that results are constant.  Each time that you perform your experiment it is called a trial. 

 

¡P      Do have only one manipulated variable during an experiment?

¡P      Do repeat the experiment more than once to verify your results?

¡P      Do have all variables set constant except for the manipulated variable?

¡P      Do organize data?

 

Draw a Conclusion

The project conclusion is a summary of the results of the project experimentation and a statement of how the results relate to the hypothesis.  Reasons for experimental results that are different to the hypothesis are included.  If applicable, the conclusion can end by giving ideas for further testing.

 

If your results do not support your hypothesis:

¡P      DON¡¦T change your hypothesis.

¡P      DON¡¦T leave out experimental results that do not support your hypothesis.

¡P      DO give possible reasons for the difference between your hypothesis and the experimental results.

¡P      DO give ways that you can experiment further to find a solution.

 

If your results do support your hypothesis:

You might say, for example, ¡§As stated in my hypothesis, I believe that light is not necessary during the germination of bean seeds.  My experiment supports the idea that bean seeds will germinate without light.  After seven day, the seeds tested were seen growing in full light and in no light.  It is possible that some light reached the ¡¥no light¡¦ containers that were placed in a dark closet.  If I were to improve on this experiment, I would place the ¡¥no light¡¦ containers in a light-proof box and/or wrap them in light-proof material, such as aluminum foil.¡¨