The District Science Fair - The Scientific Method The Scientific Method forms the basis for scientific and engineering research. You have probably heard parts of all of the Scientific Method in your science classes even though you might not remember all of the details. Basically, the Scientific Method is a clear and direct way of organizing your thoughts, follow a logical "cause and effect" study so that the project can be easily understood and reproduced by others.
The steps of the Scientific Method are:
FIND A PROBLEM - What do you want to know? Be curious, choose a limited subject, ask a question; identify or originate/define a problem.RESEARCH THE PROBLEM - What is already known and written about the problem? Review published materials related to your problem or question.
FORM A HYPOTHESIS - Answer your question with a hypothesis, i.e. what you think the outcome of your experiment will be. Evaluate possible solutions and make your educated guess.
PLAN AN EXPERIMENT - What do you need to use? What will you do to find out the answer to your question? Challenge and test your hypothesis through experimentation (data collection) and analysis.
COLLECT AND ANALYZE THE DATA - What happened in your experiment? Evaluate the results of your experiment and reach conclusions based on your data.
FORM A CONCLUSION - What did you learn?
REPORT THE EXPERIMENT - Tell what you learned; don't keep it a secret!
In the Science Service handbook on Student Projects, http://www.sciserv.org/isef/handbook.htm, research "is the process by which people create new knowledge about themselves or the world in which they live in order to answer a question or solve a problem. When choosing your topic, give careful thought to how your research might enhance the world and its inhabitants. Questioning is probably the most important part of scientific creativity and is often followed by an "if...then" statement. Questioning usually leads to experiments or observations."
In the area of Engineering Projects, the Scientific Method takes on a slightly different sequence. Scientists try to understand how nature works, engineers create things that never were. An engineering project should state the engineering goals, the development process and the evaluation of improvements. Engineering projects may include the following stages: 1) Define a need. 2) Develop design criteria. 3) Search literature to see what has already been done. 4) Prepare preliminary designs. 5) Build and test a prototype. 6) Retest and redesign as necessary.
The following information is taken directly from the web site created by David Morano, Assoc. Professor, Mankato State University (http://www.isd77.k12.mn.us/resources/cf/SciProjInter.html)
A confusing aspect of science is that not all fields of science arrive at conclusions in the same way. The physical sciences, like physics and chemistry, use experimental forms of the "scientific method." The physical sciences do experiments to gather numerical data from which relationships are derived, and conclusions are made. The more descriptive sciences, like zoology and anthropology, may use a form of the method that involves gathering of information by visual observation or interviewing. What is common among all sciences, however, is the making of hypothesis to explain observations, the gathering of data, and based on this data, the drawing of conclusions that confirm or deny the original hypothesis. The difference is in what is considered data, and how data is gathered and processed.
Data for a physical scientist is numbers. The numbers are often plotted on graphs. Graphs can be used to derive equations that can be used for making predictions. Data, for an anthropologist, could be a recorded interview. Interviews can be compared to other related information. Hence the distinction between the exact sciences (physical sciences that use numbers to measure and calculate results), and other sciences that use descriptions and inferences to arrive at results. If you are not aware of this difference, you could produce a written report for your science project. Your project will then only show what you know about something instead of experimentally answering questions you have about observations you have made. The information given below assumes you are doing an experimental science project that uses the experimental method to gather data and test hypothesis.
What is the Experimental Scientific Method?
The steps listed below will help you systematically investigate observations that can be tested with the experimental method. Not all questions can be dealt with by the experimental scientific method. You must choose a question or problem that can be formulated in terms of hypothesis that can be tested. Tests done to check hypothesis are called experiments. To design a suitable experiment you must make an educated guess about the things that affect the system you want to investigate. These are called variables. This requires thought, information gathering, and a study of the available facts relating to your problem. As you do experiments, you will record data that measures the effect of variables. Using this data you can calculate results. Results are presented in the form of tables or graphs. These results will show you trends related to how the variables affect the system you are working with. Based on these trends, you can draw conclusions about the hypothesis you originally made.
What Makes the Scientific Method Possible?
The existence of "cause and effect relationships" in nature is what makes experimental science possible. Hypothesis can only be verified using the scientific method described here if there is a cause and effect relationship between the variables you have chosen and the system you are studying.
What Is Experimental Science?
Experimental science is actually the search for cause and effect relationships in nature. A hypothesis is your best guess at what this cause and effect relationship is. Your conclusions will allow you to predict the result of future cause and effect relationships. If you can do this, you can harness effects to do things. Technology is the area that applies the findings of the sciences to produce machines, or do things for us.
STEPS IN DOING AN EXPERIMENTAL SCIENCE PROJECT
The steps in the experimental scientific method as usually presented are: Observation, Hypothesis, Controlled Experiment, and Conclusion. To actually do a science experiment, many more steps are needed. The following more accurately reflects the course of an actual experimental investigation.
Initial Observation: You notice something, and wonder why it happens. You see something and wonder what causes it. You want to know how or why something works. You ask questions about what you have observed. You want to investigate. The first step is to clearly write down exactly what you have observed.
Information Gathering: Find out about what you want to investigate. Read books, magazines or ask professionals who might know in order to learn about the effect or area of study. Keep track of where you got your information from.
Title the Project: Choose a title that describes the effect or thing you are investigating. The title should be short and summarize what the investigation will deal with.
State the Purpose of the Project: What do you want to find out? Write a statement that describes what you want to do. Use your observations and questions to write the statement.
Identify Variables: Based on your gathered information, make an educated guess about what types of things affect the system you are working with. Identifying variables is necessary before you can make a hypothesis.
Make Hypothesis: When you think you know what variables may be involved, think about ways to change one at a time. If you change more than one at a time, you will not know what variable is causing your observation. Sometimes variables are linked and work together to cause something. At first, try to choose variables that you think act independently of each other. At this point, you are ready to translate your questions into hypothesis. A hypothesis is a question which has been reworded into a form that can be tested by an experiment.
Make a list of your answers to the questions you have. This can be a list of statements describing how or why you think the observed things work. These questions must be framed in terms of the variables you have identified. There is usually one hypothesis for each question you have. You must do at least one experiment to test each hypothesis. This is a very important step. If possible, ask a scientist or engineer to go over your hypothesis with you.
Design Experiments to Test Your Hypothesis: Design an experiment to test each hypothesis. Make a step-by-step list of what you will do to answer each question. This list is called an experimental procedure. For an experiment to give answers you can trust, it must have a "control." A control is an additional experimental trial or run. It is a separate experiment, done exactly like the others. The only difference is that no experimental variables are changed. A control is a neutral "reference point" for comparison that allows you to see what changing a variable does by comparing it to not changing anything. Dependable controls are sometimes very hard to develop. They can be the hardest part of a project. Without a control you cannot be sure that changing the variable causes your observations. A series of experiments that includes a control is called a "controlled experiment."
Experiments are often done many times to guarantee that what you observe is reproducible, or to obtain an average result. Reproducibility is a crucial requirement. Without it you cannot trust your results. Reproducible experiments reduce the chance that you have made an experimental error, or observed a random effect during one particular experimental run.
Some Guidelines for Experimental Procedures: Select only one thing to change in each experiment. Things that can be changed are called variables. Change something that will help you answer your questions. The procedure must tell how you will change this one thing. The procedure must explain how you will measure the amount of change. Each experiment should have a "control" for comparison so that you can see what the change actually did.
Obtain Materials and Equipment: Make a list of the things you need to do the experiment, and prepare them. If you need special equipment, a local college or business may be able to loan it to you. Another source of science materials are mail order supply houses such as Edmund Scientific in Barrington, New Jersey (phone 1-609-457-8880 for a catalog). Professional science supply houses are located in larger cities. They will have just about anything you will need.
Do the Experiments and Record Data: Experiments are often done in series. A series of experiments can be done by changing one variable a different amount each time. A series of experiments is made up of separate experimental "runs." During each run you make a measurement of how much the variable affected the system under study. For each run, a different amount of change in the variable is used. This produces a different amount of response in the system. You measure this response, or record data, in a table for this purpose. This is considered "raw data" since it has not been processed or interpreted yet. When raw data gets processed mathematically, for example, it becomes results.
As you do experiments, record all numerical measurements made. Data can be amounts of chemicals used, how long something is, the time something took, etc. If you are not making any measurements, you probably are not doing an experimental science project.
Record Your Observations: Observations can be written descriptions of what you noticed during an experiment, or problems encountered. Keep careful notes of everything you do, and everything that happens. Observations are valuable when drawing conclusions, and useful for locating experimental errors.
Perform Calculations: Do any calculations needed from your raw data to obtain the numbers you need to draw your conclusions. For example, you weighed a container. This weight is recorded in your raw data table as "wt. of container." You then added some soil to the container and weighed it again. This would be entered as "wt. of container + soil." In the calculation section, do the calculation to find out how much soil was used in this experimental run:
(wt. of container + soil) - (wt. of container) = wt. of soil used Each calculated answer is entered into a table in a Results section.
Not all experiments need a calculation section. However, if you do not have any calculations you may not be using the experimental scientific method. If you have calculations to make, you probably are using the experimental scientific method.
Summarize Results: Summarize what happened. This can be in the form of a table of processed numerical data, or graphs. It could also be a written statement of what occurred during experiments.
It is from calculations using recorded data that tables and graphs are made. Studying tables and graphs, we can see trends that tell us how different variables cause our observations. Based on these trends, we can draw conclusions about the system under study. These conclusions help us confirm or deny our original hypothesis. Often, mathematical equations can be made from graphs. These equations allow us to predict how a change will affect the system without the need to do additional experiments. Advanced levels of experimental science rely heavily on graphical and mathematical analysis of data. At this level, science becomes even more interesting and powerful.
Draw Conclusions: Using the trends in your experimental data and your experimental observations, try to answer your original questions. Is your hypothesis correct? Now is the time to pull together what happened, and assess the experiments you did.
Other Things You Can Mention in the Conclusion: If your hypothesis is not correct, what could be the answer to your question? Summarize any difficulties or problems you had doing the experiment. Do you need to change the procedure and repeat your experiment? What would you do different next time? List other things you learned.
Try to Answer Related Questions: What you have learned may allow you to answer other questions. Many questions are related. Several new questions may have occurred to you while doing experiments. You may now be able to understand or verify things that you discovered when gathering information for the project. Questions lead to more questions, which lead to additional hypothesis that need to be tested.
Questions? Contact the Director, Lee Carvell, at 918-661-3450.
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