Transcript Independent Variable

SILENTLY complete the do now questions below.
1. What is the difference between an
observation and an inference?
2. You are performing an experiment
where you test how hydrogen gas reacts
with three different elements: oxygen,
nitrogen, and carbon.
A. What are you changing in the
experiment?
B. What is being observed/
measured in the experiment?
Do Now
T
Q
T
OBJECTIVE
SWBAT identify independent and
dependent variables in order to
construct an accurate hypothesis.
AGENDA
• Do Now
• Bubble Gum Lab and Variables
Notes
• Snowball
• Exit Ticket
1.5 Variables
Do Now
Notes:
Homework:
1.5 HW Worksheet
5
STEP 1 | ASK A QUSTION
Question: Which type of gum is the
best?
STEP 2 | RESEARCH YOUR QUESTION
Research: What type of gum do you usually
purchase?
What type of gum blows the best bubbles?
What happens when you chew gum for too long?
How long do you usually chew gum?
STEP 3 | CREATE A HYPOTHESIS
Hypothesis: If juicy fruit is the best
gum, then its flavor will last the
longest.
STEP 4 | DESIGN AND CONDUCT AN
EXPERIMENT
Materials:
+
+
+
+
+
+
Procedures:
•
Remove the piece of gum from the package, and
remove the wrapper. Hold up your piece of gum.
•
When I say go, put the gum in your mouth and begin
chewing.
•
As soon as you notice the gum losing flavor, look
at how long you have been chewing for (timer on the
board).
•
•
Record this time on your data table.
Share your data with your partner to find the
average.
VARIABLES
Something that can be
changed or manipulated in
an experiment
11
Example: A scientist wants to know how watching
TV affects students’ grades. The scientist allows students to
watch TV for different amounts of time and then analyzes
their school grades.
What variables are there?
VARIABLE
Something that can be
changed or manipulated in
an experiment
Independent
Variable
Dependent
Variable
13
Variable
What the
experimenter
is changing
What’s being
tested
Something that can be
changed or manipulated in
an experiment
Independent
Variable
Dependent
Variable
Found on the
X-axis
14
Example: A scientist wants to know how
watching TV affects students’ grades. The
scientist allows students to watch TV for
different amounts of time and then analyzes
their school grades.
What is the independent variable?
VARIABLES
What the
experimenter
is changing
What’s being
tested
Found on the
X-axis
Something that can be
changed or manipulated in
an experiment
Independent
Variable
Dependent
Variable
The effect the
experimenter
is studying
What’s being
measured/obs
erved
Found on the
Y-axis
Example: A scientist wants to know how
watching TV affects students’ grades. The
scientist allows students to watch TV for
different amounts of time and then analyzes
their school grades.
What is the dependent variable?
STEP 5 | ANALYZE DATA
Time Flavor Lasted
(Trial 1)
Time Flavor Lasted
(Trial 2)
Average
Gum 1
Gum 2
Gum 3
Gum 4
Gum 5
Average = (Trial 1 + Trial 2) / 2
Why do you think it is important to do two trials?
STEP 6 | REACH A CONCLUSION
• According to our data, which gum was the best?
• What data supports your conclusion?
• What are some possible errors that could have
been made?
IDENTIFYING VARIABLES
• In this experiment, what did we change?
• Which variable is this?
• In this experiment, what were we
measuring?
• Which variable is this?
Hypothesis
A testable prediction about a natural
phenomenon explaining a cause and effect
relationship.
If independent variable, then dependent
variable.
21
MIX DRY
Manipulate
Independent Variable
X-Axis
Dependent
Responsive Variable
Y-Axis
22
IDENTIFYING VARIABLES
The oceanographer measured the
temperature of water at different depths of
the lake.
What is the independent variable?
What is the dependent variable?
IDENTIFYING VARIABLES
Lemon trees will produce more lemons if
the gardener waters them every day.
What is the independent variable
What is the dependent variable?
IDENTIFYING VARIABLES
A scientist studied how much money
people with different levels of education
make.
What is the independent variable?
What is the dependent variable?
Control Variable
Also called a constant
Control variable: a variable
which DOES NOT CHANGE
during an experiment so that
results remain accurate
26
Experimental & Control Group
Experimental group: the subject(s)
being tested
Control group: the subject(s) who do
not receive experimental treatment
and are used as a comparison
(NORMAL/THE NORM)
27
Challenge: Pitfall!!
Don’t confuse control
variable with control
group.
•Control variables
or constants, stay the
same for the entire experiment
•Control group is a group that is used for
comparison
28
Example: Studying and Quiz Scores
Question: Is there a relationship between
the number of hours spent studying and
the score a student gets on the weekly
quiz?
Define the:
Independent Variable
Dependent Variable
Control Variables
Experimental Group
Control Group
29
Example: Studying and Quiz Scores
Independent Variable
Number of hours spent studying
Dependent Variable
Score on the weekly quiz
Control Variables
Amount of sleep
Content knowledge
Difficulty of the quizzes
Control Group
30
Example: Studying and Quiz Scores
Experimental Group
Students studying more (or less)
hours than normal
Control Group
Students studying the NORMAL
amount of hours
Difficulty of the quizzes
Control Group
31
In the gum experiment, what was our control
variable?
What was our experimental group?
What was our control group?
32
Lets Apply this through a
LAB!
• Our first lab…you’re “trying out” right
now…can you handle labs?
• Read Directions and listen to instructions
thoroughly
• THINK before you act.
• Goofing off = book work
33
Current Event Article about
saltwater intrusion
• Answer the critical thinking in your spiral
notebooks, do not write on the article!
• Critical Thinking: Thinking ahead about what
we’re going to learn this semester in Earth
and Environmental Science, explain the
implications (effects) that a declining
environment can have on our nation/world.
34
Seed Germination Lab
• STEP 1: QUESTION
• Based on the previous article, what is a
question that we could ask about
saltwater intrusion?
35
Step 2: RESEARCH
• Read the article provided and answer the
questions below to get some background
knowledge on saltwater intrusion
1) According to the excerpt above, what is saltwater
intrusion?
2) What is responsible for increased saltwater intrusion of
our coastal wetlands?
3) What are the negative effects of saltwater intrusion?
36
Step 3: Hypothesis
• Using what we now know about
creating hypothesis, what do we want
to test in this experiment?
• What could we measure?
37
SNOWBALL!
• On the SNOWBALL sheet, you will answer
question number 1. You will initial in the
completed by box.
• When instructed, you will crumple up your piece
of paper and hold it tightly in your hand.
• When instructed, you will close your eyes. When
Ms. Cheek says “SNOWBALL” toss your snowball
(gently) in any direction.
• When Ms. Cheek says “find a snowball,” you will
have 10 seconds to get a snowball and be
seated in your seat.
• As a class, we will correct the answers. You will
initial in the checked by box.
• Repeat.
EXIT TICKET
1) How can you identify an independent variable in the experiment?
A. It is what the experiment is measuring.
B. It is what the experimenter is changing.
C. It is what the experimenter compares the results to.
D. It is the question the experimenter is asking.
2) A student hypothesized that if students studied for a longer amount of time, then the
student will get better grades. To test this hypothesis, the student should design an
experiment with what independent variable?
A. The number of students.
B. The amount of time the students slept
C. The student’s quiz scores.
D. The class the students were taking.
3) Dr. Wayne developed a new drug to help lower blood pressure. She gave different
doses (.5 mg, 1 mg, 2 mg, 3 mg) to different patients. Dr. Wayne measured the patient’s
blood pressure after taking the drug. What is the dependent variable in this experiment?
A. The type of drug the patients get.
B. The amount of drug the patients get.
C. How many pills the patient gets.
D. The patient’s blood pressure.