Ms. Alvina Gohar
Msc Physics
Physics grade 10 Notes
Chapter # 1
T.B Page # 19: Lesson # 4
Topic # Graphing Data
Variables:
In research, variables are any characteristics that
can take on different values, such as height, age,
temperature, or test scores.
Researchers often manipulate or measure
independent and dependent variables in studies
to test cause-and-effect relationships.
• The independent variable is the cause. Its
value is independent of other variables in your
study.
• The dependent variable is the effect. Its
value depends on changes in the independent
variable.
Example: Independent and dependent variables
You design a study to test whether changes in
room temperature have an effect on math test
scores.
Your independent variable is the temperature of
the room. You vary the room temperature by
Ms. Alvina Gohar
Msc Physics
Physics grade 10 Notes
making it cooler for half the participants, and
warmer for the other half.
Your dependent variable is math test scores. You
measure the math skills of all participants using a
standardized test and check whether they differ
based on room temperature
What is an independent variable?
An independent variable is the variable you
manipulate or vary in an experimental study to
explore its effects. It’s called “independent”
because it’s not influenced by any other variables
in the study.
Independent variables are also called:
• Explanatory variables (they explain an event
or outcome)
• Predictor variables (they can be used to
predict the value of a dependent variable)
• Right-hand-side variables (they appear on the
right-hand side of a regression equation).
These terms are especially used in statistics,
where you estimate the extent to which an
Ms. Alvina Gohar
Msc Physics
Physics grade 10 Notes
independent variable change can explain or
predict changes in the dependent variable.
What is a dependent variable?
A dependent variable is the variable that
changes as a result of the independent
variable manipulation. It’s the outcome you’re
interested in measuring, and it “depends” on
your independent variable.
In statistics, dependent variables are also
called:
• Response variables (they respond to a
change in another variable)
• Outcome variables (they represent the
outcome you want to measure)
• Left-hand-side variables (they appear on
the left-hand side of a regression
equation)
The dependent variable is what you record
after you’ve manipulated the independent
variable. You use this measurement data to
Ms. Alvina Gohar
Msc Physics
Physics grade 10 Notes
check whether and to what extent your
independent variable influences the
dependent variable by conducting statistical
analyses.
Based on your findings, you can estimate the
degree to which your independent variable
variation drives changes in your dependent
variable. You can also predict how much your
dependent variable will change as a result of
variation in the independent variable.
Recognizing independent variables
Use this list of questions to check whether
you’re dealing with an independent variable:
• Is the variable manipulated, controlled, or
used as a subject grouping method by the
researcher?
• Does this variable come before the other
variable in time?
Ms. Alvina Gohar
Msc Physics
Physics grade 10 Notes
• Is the researcher trying to understand
whether or how this variable affects
another variable?
Recognizing dependent variables
Check whether you’re dealing with a
dependent variable:
• Is this variable measured as an outcome of
the study?
• Is this variable dependent on another
variable in the study?
• Does this variable get measured only after
other variables are altered?
Ms. Alvina Gohar
Msc Physics
Physics grade 10 Notes
Try by your self ( Check example Page 20 Graph)
• Mitchell gets $12 for every hour he
babysits. Graph this relationship where
the x-axis represents the number of
hours he works and the y-axis represents
the total amount of money he earns.