CATALYST 1.) Pick up your HOMEWORK PACKET and graded quizzes in the graded work folders.
2.) Answer the following questions on the LEFT PAGE:
What is an independent variable? What is a dependent variable?
Agenda
• Quick Reminders
• Quiz Tracker
• Variables•Independent •Dependent
• Practice
• Wrap Up
General Science – Tues, 09.02.2008
Quick Reminders
•Bring science fair notebook tomorrow!
•HW Packet #3 Due Friday, 09.05.2008.
• Quiz #3 on Friday, 09.05.2008.
General Science – Tues, 09.02.2008
QUIZ TRACKER
General Science – Tues, 09.02.2008
TRACKER
Quiz Grade 1 M A A E M A EQuiz Grade 2 MUnit Test GradeMidterm Grade
ObjectivesSWBAT:
Articulate what independent and dependent variables are.
Write a statement which contains independent and dependent variables.
Variables 09.02.2008
VariableDefinition“varius” (Latin)
means “changing” “able” (Latin)
is used to form words that describe (adjectives) and means “capable or worthy of”
So when you combine the two roots of the word variable you get the meaning:Something that is capable of changing
Variables 09.02.2008Origin -Varius (“changing”) + able
(“capable of”) = variable (“capable of changing”)
Variable
In a scientific experiment, a variable is anyfactor or trait or condition that can exist in
differing amounts or types.EX: The effect of weather conditions on the
amount of citrus fruit produced.
Why are variables important in scientific inquiry?
Scientists use variables in their
experiments to search forRelationships in nature.
Variables 09.02.2008Origin
Importance
-Varius (“changing”) + able (“capable of”) = variable (“capable of changing”)
- Helps find relationships in nature
Why are variables important in scientific inquiry?In other words, they design an experiment so
that changes to one item cause something else to vary (change) in a predictable way.
Variables 09.02.2008Origin
Importance
-Varius (“changing”) + able (“capable of”) = variable (“capable of changing”)
-Helps find relationships in nature- Setup expmts. to change one item & see how affects other items
Types of Variables
An experiment usually has three kinds of variables: independent, dependent, and controlled.
Today we are only going to talk about independent and dependent variables.
Independent Variable
An independent variable (IV) is a variable in the experiment that the experimenter changes or manipulates
Independent variable is
what I can change.
Variables 09.02.2008Origin
Importance
Types
-Varius (“changing”) + able (“capable of”) = variable (“capable of changing”)
-Helps find relationships in nature- Setup expmts. to change one item & see how affects other items
- Independent (IV) – experimenter changes (“Independent = I change”)
Independent Variable
As the scientist changesthe independent variable,he or she observes whathappens.
Dependent VariableThe dependent variable is
what changes when the independent variable
changes
The dependent variable is what
we measure
Variables 09.02.2008Origin
Importance
Types
-Varius (“changing”) + able (“capable of”) = variable (“capable of changing”)
-Helps find relationships in nature- Setup expmts. to change one item & see how affects other items
-Independent (IV) – experimenter changes (“Independent = I change”)
- Dependent (DV) – what changes when IV changes; what we measure
Dependent VariableThe scientist focuses his or her observations on
the dependent variable to see how it responds tothe change made to the independent variable.
The new value of the dependent variable is caused by and depends on the value of the independent variable.
Practice Identifying VariablesQUESTION 1
How much water flows through a faucet at different openings (closed, half open, fully open)?
INDEPENDENT VARIABLE
DEPENDENT VARIABLE
Variables 09.02.2008Types
Examples
-Independent (IV) – experimenter changes (“Independent = I change”)
-Dependent (DV) – what changes when IV changes; what we measure
- Q1: How much water flows through a faucet at different openings?
Practice Identifying VariablesQUESTION 1
How much water flows through a faucet at different openings (closed, half open, fully open)?
INDEPENDENT VARIABLEWater faucet opening (closed, half open, fully open)
DEPENDENT VARIABLE Amount of water flowing measured in liters per minute
Variables 09.02.2008Types
Examples
-Independent (IV) – experimenter changes (“Independent = I change”)
-Dependent (DV) – what changes when IV changes; what we measure
- Q1: How much water flows through a faucet at different openings? IV1: Water Faucet Opening (Closed / Half Open / Fully Open) DV1: Amount of Water Flowing
Practice Identifying VariablesQUESTION 2
Does heating a cup of water allow it to dissolve more sugar?
INDEPENDENT VARIABLE
DEPENDENT VARIABLE
Practice Identifying VariablesQUESTION 2
Does heating a cup of water allow it to dissolve more sugar?
INDEPENDENT VARIABLETemperature of the water measured in degrees Celsius
DEPENDENT VARIABLE Amount of sugar that dissolves completely measured in
grams
Practice Identifying VariablesQUESTION 3 (ON LEFT PAGE)
Does an electric motor turn faster if you increase the voltage?
INDEPENDENT VARIABLE
DEPENDENT VARIABLE
Practice Identifying VariablesQUESTION 3 (ON LEFT PAGE)
Does an electric motor turn faster if you increase the voltage?
INDEPENDENT VARIABLEVoltage of the electricity measured in volts
DEPENDENT VARIABLE Speed of rotation
Variables OVERVIEWIndependent Variables
What I change
Dependent Variables What is being measured
SUMMARY & PRACTICETake 3 minutes to write your summary.
When you are done, begin working on your HW Packet!