2. Experimental Method

3. The Experimental Method (Scientific Method)
Science is ultimately based on observation (perceiving objects or events using one of the five senses)
Observations often lead to questions which lead to experiments intended to answer that questions.

4. The Experimental Method
Observation (toaster doesn’t work) Question (why is the toaster not toasting) Hypothesis (toaster not plugged in) Experiment (plug toaster in, turn on, observe if toast is toasty) Conclusion (if toast is toasty, support hypothesis. If not, form another hypothesis)

5. Hypothesis
A hypothesis is a statement A hypothesis attempts to answer the experimental question A hypothesis must be testable. You have to be able to gather data!!!

6. Hypothesis
Good
If plants receive Miracle Grow, then they will grow taller.
If a female does the math problems, she will score higher than a male.
If a man uses deodorant, women will be attracted to him.
Bad
Plants will grow better when given Miracle Grow.
Girls are smarter than boys.
Smelling good is important.

7. Experiment
When a scientist performs an experiment, they have to explain…
What they used (materials)
How they did the experiment (procedure/methodology)
Procedure must be very specific!!!

8. Experiment Experiments always have at least two groups.
Control Group - group of subjects in the most “natural” situation.
Experimental Group -receives a treatment designed to test the hypothesis.
The ONLY difference between the groups is that the experimental group receives the treatment being tested!!!

9. The Variables Independent Variable - the factor you change.
What you do to your experimental group.
The treatment.
Dependent Variable - the factor you are measuring during experiment.
Shows how the treatment affected the subject
“Depends” on the IV

10. Collecting Data Qualitative vs. Quantitative data:
Quality: soft, cheery, red
Quantity: 5 ml, 4 oz., 7 m
Data should always be presented in a neat fashion, usually tables or graphs.