1. Example Experiment
Question- Does darkness affect germination rate of sunflower seeds?
Form your hypothesis and make a prediction.
If sunflower seeds are planted in total darkness, then they will germinate.

2. Designing a Controlled Experiment
Must compare between 2 groups
Experimental Group- variable is applied
Control Group- “Normal” Group

3. Variables Variables= what you’re testing 2 types
Independent Variable= What is changed
Dependent Variable= What is measured
Must only test 1 independent variable at a time

4. Control Group Variable is not applied
All other things are kept the same as in the variable group

5. Sample Size Experimental & Control group must be large
Larger groups = better experiment

6. What are the variables? Independent Variable= Amount of light
Dependent Variable = germination rate of seeds
Must have group of seeds in group in total dark

7. Control Group This group must be kept in normal day/night conditions
Temperature, humidity, acidity of soil, amount of water, planting depth are all controls
Only amount of light can be tested- otherwise something else might affect the outcome
These must be kept the same in both experimental and control groups

8. Collecting Data Qualitative- descriptions- color, shape, etc.
Quantitative- measurements- time, length, mass, etc.

9. Other Information Must be able to repeat your experiment
If outcome matches your hypothesis, then your hypothesis is supported-not proven
If results do not support your hypothesis, what should you do?
Re-form your hypothesis and re-experiment