Scientific Method

1. Scientific Method

2. 1. State the Problem • Write a question where you use the word effect • Question has an independent and dependent variable • Don’t ask a yes or no question

3. 2. Research • Learn as much as you can about the topic from books, magazines, online, prior experiments… • Use the research to make a hypothesis

4. 3. Hypothesis • A guess about the answer to your question • Based on background knowledge • “if…then…” statement

5. 4. Design an Experiment • Identify the independent and dependent variables • Independent variable: the variable the scientist changes on purpose. • Dependent variable: the factor that is changed because you changed the independent variable • Identify the constants • Constant: the factors in an experiment that you keep the same or do not change.

6. 4. Design an Experiment (cont.) • List materials • Write out the steps. Ensures you always do the experiment the same every time. • Create a data table(chart) to record the data • Independent variable in left column. • Dependent variable in right column(s).

7. 5. Data Collection and Analysis • Do the experiment • Record the data • Record other observations • Make calculations if necessary

8. Data Collection and Analysis • Graph Data • REMEMBER YOUR TAILS • T= Title. Include the name of independent and dependent variable in title name. • A= Axes. Independent on x-axis, dependent on y-axis • I = Intervals. Numbers are equally spaced. • L = Labels. Label x and y axis with variable names and measurement units. • S= Space. Fill the space with the data

9. 6. Conclusions • This should be at least a paragraph. It would be hard to do in less than half a page. • First tell what you tested • Second, describe the result • Third, tell if data supports or does not support hypothesis (do NOT use right/wrong) • Fourth, describe any mistakes you made • Fifth, tell what experiments you would like to try in the future.

10. Which Step is being Described? • The scientist thought that if an artificial sweetener was added to food then the mood and sleep patterns of users would change. • Hypothesis • Guess about answer to question. • Used an if, then statement.

11. Which Step is being Described? • The sweetener that was tested on the rats seemed to control their behavior as indicated by their mood. The data supported what the scientist thought. • Conclusion • Tells the result of the experiment. • Compares result to hypothesis.

12. Which Step is being Described? • Because human subjects are difficult to study, laboratory rats were used. One group of rats was given the artificial sweetener and the other group was not. All the rats were given an identical diet and living conditions. • Design an Experiment • Describes how the experiment is to be set up. • Independent variable is clear • Experimental constants are clear. • Dependent variable is a little unclear (what is it?)

13. Which Step is being Described? • The scientists found that the rats in the group with the artificial sweetener had 3 times the indicator chemical in their brains as the other group of rats. • Data collection and analysis • Sampling chemical levels in the brain is a form of collecting data. • Comparing the results of one group to another is the analysis.

14. Which Step is being Described? • A scientist at a leading university was concerned about a new artificial sweetener on the market. She wanted to know if this sweetener had an effect on the mood and emotions of those who consumed it. • Stating the Problem • She uses the word effect. • It is clear that this problem or question could lead to an experiment.