Vocabulary:
Manipulated variable => responding variable
independent variable => dependent variable
“x” => “y”
Cause => effect
AIM: What are Variables?
VARIABLES
WHAT IS A MANIPULATED VARIABLE?
Thing that you “change” in an Experiment
Manipulated Variable
Independent Variable
“x”
VARIABLES
WHEN YOU CHANGE THE MANIPULATED VARIABLE
THE RESPONDING VARIABLE
IT CHANGES ALSO!
AS an example:AS an example:
How would you devise an experiment How would you devise an experiment which would test whether a fertilizer which would test whether a fertilizer
actually helped plants grow?actually helped plants grow?
What is the independent variable?What is the independent variable?
What is the dependent variableWhat is the dependent variable
VARIABLES
AS an example:AS an example:
How would you devise an experiment How would you devise an experiment which would test whether sunlight which would test whether sunlight
actually helped plants grow?actually helped plants grow?
What is the independent variable?What is the independent variable?
What is the dependent variableWhat is the dependent variable
VARIABLES
AS an example:AS an example:
How would you devise an experiment How would you devise an experiment which would test whether Mr. Z’s which would test whether Mr. Z’s
fish could live in salt water?fish could live in salt water?
What is the independent variable?What is the independent variable?
What is the dependent variableWhat is the dependent variable
VARIABLES
EXAMPLE: Suppose you did a study EXAMPLE: Suppose you did a study which concluded that the more a which concluded that the more a student studies the higher grade a student studies the higher grade a
student receivesstudent receives
What is the manipulated variable?What is the manipulated variable?
What is the responding variableWhat is the responding variable
VARIABLES
EXAMPLE: Suppose you did a study EXAMPLE: Suppose you did a study which concluded that the older which concluded that the older people become, then the higher people become, then the higher
becomes their IQbecomes their IQ
What is the manipulated variable?What is the manipulated variable?
What is the responding variableWhat is the responding variable
VARIABLES
EXAMPLE: Suppose you did a study EXAMPLE: Suppose you did a study which concluded that the more which concluded that the more
children watch TV, then the lower children watch TV, then the lower their SAT scorestheir SAT scores
What is the manipulated variable?What is the manipulated variable?
What is the responding variableWhat is the responding variable
VARIABLES
EXAMPLE: Suppose you did a study EXAMPLE: Suppose you did a study which concluded that the more which concluded that the more
fertilizer a plant receives, then the fertilizer a plant receives, then the more flowers it produces more flowers it produces
What is the manipulated variable?What is the manipulated variable?
What is the responding variableWhat is the responding variable
VARIABLES
EXAMPLE: Suppose you did a study EXAMPLE: Suppose you did a study which concluded that oceans which which concluded that oceans which
have a higher “salt” content will have have a higher “salt” content will have less fish less fish
What is the manipulated variable?What is the manipulated variable?
What is the responding variableWhat is the responding variable
VARIABLES
EXAMPLE: Suppose you did a study EXAMPLE: Suppose you did a study which concluded that the faster a car which concluded that the faster a car travels, the less its fuel economy will travels, the less its fuel economy will
be be
What is the manipulated variable?What is the manipulated variable?
What is the responding variableWhat is the responding variable
VARIABLES
EXAMPLE: Suppose you did a study EXAMPLE: Suppose you did a study which concluded that as the average which concluded that as the average
temperature in a pond increases, then temperature in a pond increases, then the the average number of frog the the average number of frog “croaks” “croaks” (per minute)(per minute) increases increases
What is the manipulated variable?What is the manipulated variable?What is the responding variableWhat is the responding variable
VARIABLES
Those we try to Change (Cause)
• Independent Variable
• Manipulated Variable
• X variable
Those we try to Change (Cause)
• Independent Variable
• Manipulated Variable
• X variable
The result of the Change (effect)
• dependent variable
• responding variable
• Y variable
The result of the Change (effect)
• dependent variable
• responding variable
• Y variable
Consider This: Will a house plant grow better in a warm
room or a colder room
What is going to be the manipulated variable?
The Temperature of the Room
VARIABLES
Consider This: Will a house plant grow better in a warm
room or a colder room
What is going to be the responding variable?
Plant Growth
VARIABLES
EXAMPLE: Lava from a Hawaiian EXAMPLE: Lava from a Hawaiian volcano travels a 20 feet every minute volcano travels a 20 feet every minute
What is the manipulated variable?What is the manipulated variable?
What is the responding variableWhat is the responding variable
Time => distanceTime => distance
VARIABLES
1. Identify the problem being investigated
2. Identify the manipulated variable and the responding variable
3. Identify which one CAUSES the other one to change
TIPS FOR IDENTIFYING VARIABLES
VARIABLES
REVIEW Manipulated variable => responding variable independent variable => dependent variable
“x” => “y”
VARIABLES
Class Handout Activity pg. 46: Controlling Variables
Graph Data Table
VARIABLES
Homework:
Internet Questions
Finish a Graph of the Data Table
VARIABLES