1. An Organized Approach to Solving Problems
SCIENTIFIC METHOD
An Organized Approach to Solving Problems

2. Scientific Method
Organized problem solving
Not a single method

3. Steps of the Scientific Method
Define the Problem
Collect Information About the Problem
Form a Hypothesis
Experiment
Collect Results
Conclusion
Repeat

4. Step 1. Problem What are to trying to find out?
- Usually based on observations
- stated as a question
Example: I notice that on warm nights crickets seem
to chirp more often
Problem = Does temperature affect the rate of cricket chirps?

5. Step 2. Collect Information About the Problem
Information can be gathered from:
- your own observations
- published research
textbooks, articles, internet etc…

6. Step 3. Form a Hypothesis A possible solution to your problem
Must make a prediction
Must be possible to be disproved
- UFOs exist is not a scientific hypothesis because it is impossible to disprove

7. Formal Hypothesis
A formal hypothesis used in an experiment should be stated in If…Then form.
- It relates directly to the experiment to be conducted and explains the expected outcome
-If I do this…..then that will happen.
Example: If I raise the temperature I keep crickets in, then they will chirp more.

8. Step 4. Test Your Hypothesis-Experiment
Experiment must be controlled
- tests only one thing at a time
A controlled experiment compares a control group with an experimental group
The control group provides a normal standard against which the biologist can compare results of the experimental group.
The experimental group is identical to the control group except for the one factor being tested
- the variable being tested is the independent variable
Emphasize that there is only one difference between two groups

9. Experimental Design Needs to be repeatable Should test a large sample
Should be without bias

10. Variables Variable = anything that can change in an experiment
Controlled variables = What do I keep the same?
Independent variables = What do I change?
aka Manipulated variables
Dependent variables = What do I measure?
aka Responding variables

11. Question
Independent Variable (What I change)
Dependent Variables (What I observe)
Controlled Variables (What I keep the same)
How much water flows through a faucet at different openings?
Water faucet opening (closed, half open, fully open)
Amount of water flowing measured in liters per minute
The Faucet
Water pressure, or how much the water is "pushing"
"Different water pressure might also cause different amounts of water to flow and different faucets may behave

12. Cricket Experiment 20 crickets grown in a 10 gallon aquarium
Control Group
Experimental Group
20 crickets grown in a 10 gallon aquarium
12 hours of light/day
Fed 5 g Acme Cricket Food
Kept at 60 degrees F
20 crickets grown in a 10gallon aquarium
12 hours of light/day
Fed 5 g Acme Cricket Food
Kept at 80 degrees F

13. Step 5 Data and Results
Data = observations or measurements - Quantitative = number data 10 chirps/minute - Qualitative = observations color changed to orange Results = Processed data – makes the meaning of the data more clear. Allows you to see trends or patterns. Calculate an average, graph of data etc..

14. Graphing Your Data
Independent Variable- the factor that is changed before the experiment begins. It goes on the x-axis. Sometimes called manipulated
Dependent Variable- the factor that you ran the experiment to measure, sometimes called results. It goes on the y-axis. Sometimes called responding

15. Sample Graph Dependent Variable: on the Y Axis
Independent Variable on the X Axis

16. Conclusions Was your hypothesis correct?
- do the results support your hypothesis
What are possible sources of error?
What next? – What question could you study next?
Why is this important?

17. Repeat Your Work/Publish
Repeat experiment to confirm your results.
When scientists have completed their
work, they publish their results
- this informs other scientists of their
findings

18. Theory
A hypothesis that has been tested repeatedly and shown to be correct becomes a theory
Theories can explain current observations and predicts new observations
A theory is as close to certainty as you get in science

19. Vocabulary to Know and Love
hypothesis
experimental group
control group
variable
controlled variables
independent/manipulated variable
Dependent/responding variable
data
quantitative data
qualitative data
Results
theory