1. Scientific Method

2. What is a method?  A method is the steps that are taken to complete a task.  The scientific method is the steps that a scientist takes to do research successfully.  Helps scientists stay organized.  Gives a common process for all scientists to follow to ensure it is uniform.  Turn to your partner and describe the method to a process!

3. The Steps of the Method:  1. Observation  2. Hypothesis  3. Design Controlled Experiment  4. Record & Analyze Results  5. Make Conclusions  6. Share Research

4. Observation/Asking a Question  Finding a pattern  Seeing something interesting or important and asking questions  What might be a scientific observation you would like to know the answer to?

5. Hypothesis  Making an educated guess of what the outcome to your question might be  Prediction to the question or observation  Must be testable—meaning you have to be able to create an experiment that supports or refutes your hypothesis

6. Design Controlled Experiment  Factors in an experiment that are changed are called variables  Some examples of variables—Temperature, pressure, time, concentration  During a Controlled Experiment, only one variable is changed at a time.  Why would we only want to change one variable at a time?  An experiment is based on a control group & an experimental group  The groups are the exact same except the control group does not have the factor that is being tested

7. Page 7 Example: In order to test the effectiveness of a new vaccine, 50 volunteers are selected and divided into two groups. One group will be the control group and the other will be the experimental group. Both groups are given a pill to take that is identical in size, shape, color and texture. Describe the control group. Describe the experimental group. What variables are kept constant? What variable is being changed? Even though the volunteers are given identical looking pills, the control group will not actually receive the vaccine. This group will receive the vaccine. The size, shape, color, and texture of the pill. Whether or not the pill contains the vaccine.

8. Variables  Three Types of Variables:  Independent—Changed by the scientist  Dependent—Changes because of the change in the independent variable  Controlled—Variables that remain constant, do not change! Example : I want to know if a plant will grow more if I increase the amount of light…  What are(is) the…  independent  dependent  controlled variables

9. Data Collection & Analysis  Create some way to organize data  Charts, graphs, tables, etc.  Analyze—Does the data support or refute your hypothesis?  DO NOT SAY PROVE/DISPROVE!!!

10. Data Collection in Experiment  Two types of data can be collected:  Quantitative—numbers, measurements  Example: The plant grew 5 feet  Qualitative—observations, descriptions, data that cannot be counted or measured  Example: The liquid changed from purple to red

11. Drawing Conclusions  What can you say about your hypothesis?  Just because your results say one thing, it does not mean that it is fact!!!  Experiments are carried out with many different tests and trials to see if the results are consistent  Results should always come out the same during trials before a valid conclusion can be made  Take into account error! Maybe you did not get the results you thought you would because some error was made along the way. Did you make a mistake?  Was there some type of experimental error? Something that, no matter what, you could not take into account when designing your experiment?

12. Communicate Results  Scientists share results  Write a paper  Present your data & conclusion  Be prepared to share with people what you found and how you found it!

13. Practice Problem Billy and Jane are dairy farmers and have several cows. They want to determine what they can do to help cow digestion. They decide to give the cows different types of supplements in their food to determine which one will help the most with digestion: yeast, yucca extract, and sodium bicarbonate. Hypothesis: If…(independent variable) then…(dependent variable) Ex: If the cows are fed yeast, then their digestive health will improve

14. Setting up the Experiment  5 cows fed plain grass  5 cows fed grass with added yeast  5 cows fed grass with added yucca extract  5 cows fed grass with added sodium bicarbonate 1. Cows will be fed everyday at the same time 2. They will be fed the same number of days 3. The cows will be fed the same type of grass 4. Billy & Jane will collect data daily

15. What is the control group?  The group that should not show major changes and the independent variable cannot have an effect on it.  Standard to compare all other tests to  Ensures that nothing else is causing an effect in the other groups besides the independent variable.  What is our control group? NO SUPPLEMENT IN FOOD

16. Variables  What is the independent variable? type of supplement  What is the dependent variable? digestive health  What are the controlled variables? amount of feed, type of grass, how often the cows are fed

17. Data Collection  Billy & Jane collected data. By the end of the experiment these were their final results: What can you determine from Billy & Jane’s results? Was your hypothesis supported or rejected? Type of Supplement No Supplement YeastYucca Extract Sodium Bicarbonate Amount of fiber digesting bacteria (g) 12g120g fiber digesting bacteria 10g11g

18. Analysis  Was your hypothesis supported or rejected?  What can you determine from Billy & Jane’s results?  How can you make this determination?