The Scientific Method

The Scientific Method Science: the quest to answer questions about the world around us The Scientific Method: the process we use to answer these questions

The Scientific Method The Scientific Method involves 7 steps: Observation Question Research Hypothesis Experiment Analyze Conclude

The Scientific Method Observation- You observe something in the world, using your senses. - Recognize a problem that needs to be solved AH—Look at this!

The Scientific Method Question- You ask a question about what you observe. State the problem. Research – Find out background information about your question/problem.

The Scientific Method Hypothesis- an educated guess about the answer to your question that can be tested by an experiment

The Scientific Method Controlled Experiment – Make sure only one “variable” is tested at a time and that there is a “control” for comparison “variable” – something that changes independent: the factor that is varied dependent: the factor that is measured “control” – does not contain the IV, serves as a comparison

The Scientific Method Data - Collecting and analyzing data from the experiment that will help to determine if the hypothesis is correct. Qualitative = describing with words “It’s really hot and humid outside” Quantitative = describing with numbers “It’s 95 degrees and 90% humidity outside”

The Scientific Method Analysis- Analyze the data to verify the hypothesis. - Verify if the hypothesis you stated is supported or rejected by the data from the experiment.

The Scientific Method Conclusion- do your results support or reject your hypothesis? - Many experiments need to be conducted with the same results to support the same hypothesis before the information is accepted or published. -Your results can now be shared with others.

The Scientific Method No experiment is a failure! Even if you did not support your original claim, you did find out information that does not work

The Scientific Method Theory: Different from the “nonscientific” definition, in which theory means “guess”. A set of related hypothesis that have been tested and confirmed many times by many scientists and a lot of data. As new data is collected, a current theory can be altered.

Case Study Problem: A gardener buys two fertilizers for his tomato plants (fertilizer A and fertilizer B). This gardener wants to know which fertilizer will make his tomato plants produce more fruit.

Case Study Now take a few minutes to apply the steps of the scientific method to this problem. Explain each step Identify the control Identify the variables Determine whether the data is quantitative or qualitative

Case Study Research what is known about the problem: The gardener reads the labels of each fertilizer and tries to find any information he can about these two brands of fertilizers

Case Study Hypothesize: The gardener decides that fertilizer A will probably work better based on the research that has been done on the two products.

Case Study Design and Conduct an experiment: The gardener uses fertilizer A on five of his tomato plants and fertilizer B on the other five tomato plants he has in the garden. He also grows five plants with no fertilizer at all. The gardener is careful to treat the 15 tomato plants in the same manner (watering, exposure to sunlight, soil, etc), except for the use of the different fertilizers in the first two groups.

Case Study Design and conduct an experiment cont… Variable: Control: the fertilizer used in each part of the experiment Control: the five tomato plants not being given the fertilizer (serves as the comparison)

Case Study Collecting and analyzing data After a determined period of time, the gardener checks the amount of fruit on the 15 plants in the study. Because the gardener is counting the number of fruit on each plant, this is quantitative data.

Case Study Data cont… The results show that the five plants grown with fertilizer B have almost twice as much fruit as the five plants grown with fertilizer A. The five plants without any fertilizer have the least amount of fruit.

Case Study Conclusion: The initial hypothesis that fertilizer A would work better to produce more fruit than fertilizer B was wrong. Even though his hypothesis was wrong, the gardener learned valuable information

Case Study Repeatability and sharing results In order to be a valid experiment with valid results, it needs to be repeatable with the same outcome.