Here are the key variables that were kept the same between the control and experimental groups in this Lincoln Peas lab report:
- Volume of liquid added to each petri dish (10 mL)
- Volume of each solution (50 mL)
- Number of Lincoln Peas in each petri dish (5 peas)
- Size of the Lincoln Peas (all relatively the same size)
- Amount of paper towel in each petri dish (5 pieces)
- Environmental conditions (temperature, light, and location for all dishes)
- Source of water (distilled water for all conditions)
Keeping these variables the same between the groups allowed the researchers to isolate the independent variable being tested, which was the