1. Comparing controls, dependent variables, and independent variables

2. What is a control? A standard used to compare the outcomes of an experiment’s effect A standard used to compare the outcomes of an experiment’s effect Control group: a group of subjects that is not exposed to an experimental procedure in order to compare a the procedure’ effect on a group of subjects that are exposed to an experimental procedure Control group: a group of subjects that is not exposed to an experimental procedure in order to compare a the procedure’ effect on a group of subjects that are exposed to an experimental procedure

3. What is a variable? any factor, trait, or condition that can exist in differing amounts or types any factor, trait, or condition that can exist in differing amounts or types 2 types 2 types Independent Independent Dependent Dependent

4. Independent variable Stands alone Stands alone Isn’t changed by other variables you are trying to measure (may be more than 1 type but all belong to the same group) Isn’t changed by other variables you are trying to measure (may be more than 1 type but all belong to the same group) What you are testing What you are testing Example: age Example: age Main goal: trying to see if the independent variable causes a change in other variables Main goal: trying to see if the independent variable causes a change in other variables

5. Dependent variable Something that depends on other factors Something that depends on other factors It changes, It changes, Usually has a numeric value Usually has a numeric value What you measure What you measure Example: test score Example: test score Main goal: trying to find out what makes the dependent variable change the way it does Main goal: trying to find out what makes the dependent variable change the way it does

6. Remembering the difference… (Independent variable) causes change in (Dependent variable) and it isn’t possible that (Dependent variable) could cause change in (Independent variable).

7. For Example ( Previous time spent studying) causes a change in (Test score) and it isn’t possible that (Test score) could cause a change in (previous time spent studying). (unless you have a time traveling machine)

8. Toilet Paper Lab Independent variable Independent variable  Types of toilet paper Dependent variable Dependent variable  Number of pennies placed on the toilet paper until it broke (Types of toilet paper) causes a change in (number of pennies held) and it isn’t possible that (number of pennies held) could cause a change in (types of toilet paper).

9. Example 1

10. Example 2