►
Examples
: A teaching method, a medical treatment, or training regimen.
Dependent variable(DV):
►
The outcome of the changes brought by an independent variable.
►
A phenomenon that is affected by the
researcher’s
manipulation of an-
other phenomena.
►
Examples
: Achievement is the effect of a teaching method, cure or not
the effect of a medical treatment, and higher skill level or not (achieve-
ment) the effect of a training regimen.
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Types ofVariable
Viewpoint of causal relationships
From a viewpoint of causal
relationships
3
Extraneous variables:
►
Other variables, not measured in a study, may increase or decrease the
magnitude or strength of the relationship between IV and
DV.
►
Example
:
When investigating the effect of television watching (IV) on
achievement (DV), type of program is an extraneous variable.
4
Intervening (mediating) variable:
►
A connecting or linking variable that links the IV and DV. This is a
situation where the relationship between IV and DV
can’t
be established
without the intervention of another variable.
►
Example
:
When studying the association between income and longevity,
access
to medical care is an intervening variable.
Independent
Dependent
Extraneous
Intervening
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Types ofVariable
Viewpoint of causal relationships
Examples
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Types ofVariable
Viewpoint of causal relationships
Examples
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Types ofVariable
Viewpoint of causal relationships
Examples
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Types ofVariable
Viewpoint of causal relationships
Exercise
List and label the variables in the following situations and illustrate by means
of diagrams the relationship among the variables.
1
2
3
4
A study suggested that elementary students who watch TV more than 3 hours
a day aremore likely to be overweight than students who watch less TV.
People are de-motivated to consume alcohol knowing the consequence that it
damages the liver leads to liver cirrhosis. Perhaps behavioral therapy works
better for males and cognitive therapy works better for females.
Research suggests that children who eat hot breakfast at home perform better
at school. Many argue that not only hot breakfast but also parental care of
children before they go to school has an impact on
children’s
performance.
Lucy examined relationships between middle-school
students’
self-esteem and
their performance in Mathematics. Her data analysis indicated that students
with higher self-esteem perform better than those with lower self-esteem. Her
investigation further revealed that students with higher self-esteem are more
willing to invest effort in solving mathematics problems.
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