Do Now You have 5 minutes to answer the following question(s). When you are done take out your binder and turn to the notes section. • What factors affect your ability to make an “A” in a class? • What factors affect how fast a plant grows?
Feb 14, 2016
Do Now
You have 5 minutes to answer the following question(s). When you are done take out your binder and turn to the notes section.
• What factors affect your ability to make an “A” in a class?
• What factors affect how fast a plant grows?
Announcements/ Expectations
• You will start seeing grades go in this weekend.
• Headings• Prepared for class– Binder, divider and composition notebook
• Class Points
Variables and Hypothesis
What is a variable?
• Scientists use an experiment to search for cause and effect relationships in nature.
• A variable is any factor, trait, or condition that can exist in differing amounts or types. An experiment usually has three kinds of variables: independent, dependent, and controlled.
Independent Variable
• Also called the manipulated variable.• This is the variable that the scientist will manipulate
to see how it affects the dependent variable. • The independent variable is the one that is changed
by the scientist. • To insure a fair test, a good experiment has only
one independent variable. • As the scientist changes the independent variable,
he or she observes what happens.
Dependent Variable• Also called the responding variable.• Are the result of something that the scientist
has changed • Is actually being measured in the experiment• The scientist focuses his or her observations
on the dependent variable to see how it responds to the change made to the independent variable.
Controlled Variable
• Also called the constant variable• The control variable will be the one that does
not change.• Most experiments have more than one
controlled variable. • The control variable is something that is
constant and unchanged in an experiment.
Form a HypothesisHypothesis: an educated guess or prediction; an “if, then” statement
If independent/manipulated variable, then dependent/responding variable.
Break
Example• Mandy set up an experiment to show the
relationship between plant growth and amount of water given to the plants.
• The stated problem was "Does the amount of water affect the growth of bean seeds?”
• Mandy's hypothesis was written in "if-then" format:
• If I don't water my plants, then they will not grow.– Independent variable- Amount of water– Dependent variable- Plant growth
Use this hypothesis to identify the variables
If I leave all the lights on all day, then my electric bill will be high.
IV: ______________________
DV: ______________________
If I drink Mountain Dew before bed, then I will not sleep very much.
IV: ______________________
DV: ______________________
If I brush my cat more, then there will be less fur on my furniture
IV: ______________________
DV: ______________________
Now read the following experiment and identify the independent and dependent variables and write a
hypothesisElizabeth wanted to test if temperature affected how fast milk
goes bad and curdles. She left milk in a room temperature closet, a fridge, and a oven that was turned on low heat. She then measured how rotten the milk was after 10 days.
Hypothesis: ______________________________
IV: ____________________________________
DV: ____________________________________
Independent Practice
Worksheet ExampleHypothesis:______________________________
IV: ____________________________________
DV: ____________________________________
Independent Practice
Exit Ticket
What is an independent variable?
What is a dependent variable?
What is a hypothesis?
ACT Prep