Controlling Variables
Let’s learn about the 3 types of variables! Hypothesis The hypothesis is an educated guess about the relationship between the independent and dependent variables. Let’s learn about the 3 types of variables!
The 3 types of variables!
Independent Variable Independent Variable – the one thing that is changed in an experiment What is tested What is manipulated
Dependent Variable Dependent Variable: the variable that is affected by the change in the independent variable What is measured What is observed The data collected during the investigation the factor that may change as a result of changes made in the independent variable.
All experiments should have a control group. Controlled Variables Constant: a variable that is not changed Also called controlled variable Allows for a “fair test” Control group: exposed to the same conditions as the experimental group, except for the variable being tested. Serves as the standard of comparison. The control group may be a “no treatment" or an “experimenter selected” group. All experiments should have a control group.
Identify the variables: Hypothesis: If we add more air, the ball will bounce higher. Independent variable: the amount of air in the ball Dependent variable: How high the ball bounces Controlled variables: type of ball, drop the ball from the same height, drop the ball on the same surface
Identify the variables: Hypothesis: If a plant gets sunlight it will grow taller. Independent variable: sunlight Dependent variable: Growth of plants Controlled variable: Type of plant, pot, dirt, water, location, fertilizer