Experimental Variables Notes and Practice
Experimental Variables: Independent Variable (IV): The variable purposely changed by the experimenter Control: One of the IV’s that is standard (normal) Dependent Variable (DV): The outcome of the experiment (what the experimenter is measuring) Controlled Variables (Constants): Variables that remain the same during the experiment
Practice #1 Question/Problem Experimental Variables What would my fuel efficiency (mpg) be if I filled my car tires with helium instead of air? Procedures? Independent Variable: Control: Dependent Variable: Constants:
Practice #2 Question/Problem Experimental Variables What will my 1-mile running time be based on the amount of water I drink? Procedures? Independent Variable: Control: Dependent Variable: Constants:
Practice #3 Question/Problem Experimental Variables How tall will a plant grow if I feed it MiracleGrow in addition to water? Procedures? Independent Variable: Control: Dependent Variable: Constants:
Graphing
Graphing T = Title A = Axis I = Interval L = Labels (w/ units)
Axis D = Dependent Variable R = Responding Variable Y = Y-axis M = Manipulated Variable I = Independent Variable X = X-axis
Type of Graph If IV is categorical = Bar Graph If IV and DV are continuous = Scatter Plot If change over time = Line Graph
Practice #1 What would my fuel efficiency (mpg) would be if I filled my car tires with helium instead of air? Type of graph: Type of Gas Air Helium Nitrogen Argon Oxygen Mpg 27.1 28.7 27.9 26.7 27.2
Practice #2 What will my 1-mile running time be based on the amount of water I drink? Type of graph: Volume of Water 0 L 0.5 L 1.0 L 1.5 L 2.0 L Run Time (min.) 6:01 5:54 5:51 5:34 5:41
Practice #3 How tall will a plant grow if I feed it MiracleGrow compared to water? Type of graph: Plant Height Days 1 3 5 7 9 Water 0.8 cm 1.1 cm 1.5cm 2.0 cm 2.3 cm Miracle Grow 0.9 cm 1.3 cm 1.8 cm 2.4 cm 3.1 cm
Practice #1 What would my fuel efficiency (mpg) would be if I filled my car tires with helium instead of air? Type of graph: Type of Gas Air Helium Nitrogen Argon Oxygen Mpg 22.1 28.7 25.9 18.7 20.2
Practice #2 What will my 1-mile running time be based on the amount of water I drink? Type of graph: Volume of Water 0 L 0.3 L 0.7 L 1.4 L 1.6 L 2.0 L 2.2 L 2.4 L Run Time (min.) 6:01 5:54 5:51 5:34 5:41 5:38 5:33 5:39
Practice #3 How tall will a plant grow if I feed it MiracleGrow compared to water? Type of graph: Plant Height Days 1 3 5 7 9 11 13 15 Water 0.8 cm 1.1 cm 1.5 cm 2.0 cm 2.3 cm 2.7 cm 3.0 cm 3.2 cm Miracle Grow 0.9 cm 1.3 cm 1.8 cm 2.4 cm 3.1 cm 3.5 cm 3.9 cm 4.6 cm