I-N-D-E-P-E-N-D-E-N-T variables, dependent variables, and constants

1
I-N-D-E-P-E-N-D-E-N-T variables, dependent
variables, and constants

• Catalyst
• What question is this data table answering?
• What is one conclusion we can make from looking
  at this data table?
• ----------------------------------
• Write a hypothesis to answer this question Why
  is hydro (water) power used so often?
• ----------------------------------
• Weekly Goal

Write in complete sentences! Dont talk
during the Catalyst!
2
Todays Agenda

• Catalyst
• Quiz grades
• Variables Notes and Practice Time
• I-N-D-E-P-E-N-D-E-N-T!
• DEPENDENT
• CONSTANTS
• Exit Question
• HOMEWORK TONIGHT!
• UNIT TEST ON FRIDAY!

3
Quiz Class Averages
2CHEM 78
3BIO 73
4BIO 58
4
Objectives

• By the end of today, SWBAT
• Identify independent and dependent variables, and
  constants in a scientific experiment

5
Experimentation

• Key Point 1 A proper experiment always has an
  independent variable and dependent variable.
• The purpose of an experiment is to test how
  changing ONE THING affects something else.

6
Variables
Green text Im teaching you a
definition. Write it.

• Independent Variable what causes the change we
  are measuring (acts independently)
• Dependent variable what gets changed (depends on
  other things)
• Remember
• Variables are always CATEGORIES of things time,
  amount, frequency, size, type
• Variables are NEVER specific things!!!

7
Teacher Models

• Scientists have discovered something shocking if
  you eat a lot of candy, then you will gain fat. ?
  What is the independent variable?
• Eat a lot of candy
• Type of candy you eat
• Amount of candy you eat
• How much weight you gain

8
Teacher Models

• Happy students learn more in school. So, Ms. S
  believes that starting school later would
  increase test scores. What is the dependent
  variable?
• Starting school later
• Happy students
• Time that school starts
• Test scores

9

• NEW PROCEDURE!
• WHITEBOARDS!

10
Whiteboard Practice Goal 90 s

• When Ms. S says GO!
• Send one member of your group to get whiteboards
  and markers for everyone (back shelf)
• Send up another member of your group to get
  erasers one for every two people (lab table)

11
Set Up Your Whiteboard
1 a. b. c. d.
2 a. b. c. d.
3 a. b. c. d.
4 a. b. c. d.
12
Whiteboards 1

• Ms. S believes that the more you study, the
  better grades youll earn. What is the
  independent variable?
• Studying more
• Amount of time you study
• Grade earned
• Type of test

13
Whiteboards 2

• Tyranea is always cold in class. She hypothesizes
  that if she wears many layers of clothing to
  school, then she will be warmer. What is the
  dependent variable?
• Number of layers Tyranea wears
• How cold Tyranea is
• Temperature of the room
• Tyranea will be warmer

14
Whiteboards 3

• Ms. Sanacores students want to test how easily
  bought off she is. Students who give her an apple
  get a C. Students who give her peanut MMs get
  an A. What is the independent variable?
• Type of food
• Apples and MMs
• A on the report card
• Report card

15
Whiteboards 4

• Jenika hates running, but loves listening to
  music. She believes that if she listens to music
  while running, then she will run more often. What
  is the dependent variable?
• She will run more often
• Listens to music while running
• Frequency that Jenika runs
• What Jenika listens to

16
If youre having trouble
WRONG
RIGHT

• 4 minutes
• 26 mg of baking soda
• Lifting weights every day
• Medium t-shirts
• Bullfrog
• 16 candles
• Never gets sick

• Time to get dressed
• Amount of baking soda
• Frequency of lifting weights
• Size of t-shirts
• Type of frog
• Number of candles
• Degree of health

17
Review

• Ms. S believes that the more you study, the
  better grades youll earn. What is the
  independent variable?
• Studying more
• Amount of time you study
• Grade earned
• Type of test

18
Review

• Tyranea is always cold in class. She hypothesizes
  that if she wears many layers of clothing to
  school, then she will be warmer. What is the
  dependent variable?
• Number of layers Tyranea wears
• How cold Tyranea is
• Temperature of the room
• Tyranea will be warmer

19
Review

• Ms. Sanacores students want to test how easily
  bought off she is. Students who give her an apple
  get a C. Students who give her peanut MMs get
  an A. What is the independent variable?
• Type of food
• Apples and MMs
• A on the report card
• Report card

20
Review

• Jenika hates running, but loves listening to
  music. She believes that if she listens to music
  while running, then she will run more often. What
  is the dependent variable?
• She will run more often
• Listens to music while running
• Frequency that Jenika runs
• What Jenika listens to

21
Guided Practice Worksheet

• 8 minutes to complete independently (on your own,
  silently)
• 3 minutes to compare answers
• WORK HARD. It will help you with homework tonight.

22
Constants

• Key Point 2 Everything but the independent and
  dependent variable must be kept constant.
• Constant variable we keep the same
• If many different things change at once, we dont
  know what causes the change!

23
Example

• Lets say we want to design an experiment to
  determine what causes GSP to win fights.

24
Cause and Effect!
Number of fights that GSP wins
25
Answer in notes

• Jay-Z hypothesizes that if he stops cussing, then
  he will sell fewer CDs because students like
  cussing.
• What is the IV?
• What is the DV?
• What are the constants?
• Remember, variables are
• CATEGORIES.

26
If Jay-Z stops cussing, then he will sell fewer
CDs because students like cussing.

• IV
• Frequency that Jay-Z cusses
• How often Jay-Z cusses
• Amount of curse words in Jay-Z songs
• DV
• Number of CDs Jay-Z sells
• How many CDs Jay-Z sells
• Constant
• Amount of money CDs cost
• Number of tracks on each CD
• How good each CD is

27

• CLEAR YOUR WHITEBOARD!

28
Set Up Your Whiteboard
IV DV Constant(s)
29
Practice

• You want to know when in the year there are the
  most love bugs. Every night, you record how many
  love bugs you find outside.

Time of year (season/month)
IV DV Constant
Amount of love bugs
30
Practice

• Jenika needs to run a 6 minute mile to pass PE.
  She believes that if she runs every day, then she
  will be able to run faster.

IV DV Constant
Frequency that Jenika runs
Mile time
31
Practice

• Students of different genders were given the same
  puzzle to assemble. The puzzle assembly time was
  measured.

IV DV Constant
Type of gender
Time to assemble puzzle
32
If there are more students, then there will be
more school buses.
IV DV Constant
Amount of students
Number of school buses
33
If the cost of beignets increases, then fewer
will be sold.
What depends on what? IV DV Constant
Amount each beignet costs
Number of beignets sold
34
If the Saints sign more free agents, then they
will win more games.
IV Number of free agents DV Number of games
won Constant
35
Conclusion

• A proper experiment always has an independent
  variable and dependent variable.
• Independent Variable what causes the change we
  are measuring
• Dependent variable what gets changed
• Constant variable we keep the same

36
Exit Question

• Lets say you want to figure out if drinking milk
  actually makes you taller. So you drink a glass
  of milk every day, and record your height every
  day.
• What is the independent variable?
• What is the dependent variable?
• What are at least two constants?

Write in complete sentences! Dont talk during
the Exit Question!