4. VARIABLES
- Is derived from the root word “vary.”
- are elements, entities, or factors that can change (vary);
- for example, the outdoor temperature, the cost of
gasoline per gallon, a person’s weight, and the mood of
persons in your extended family are all variables. In other
words, they can have different values under different
conditions or for different people.
5. EXAMPLE OF VARIABLES
1.the outdoor temperature
2.the cost of gasoline per gallon
3.a person’s weight
4.the mood of persons in your extended family.
In other words, they can have different values under
different conditions or for different people.
6. RELATIONSHIP OF VARIABLES
Researchers often study the relationship
between (or among) either:
1. two or more quantitative variables
2. one categorical and one quantitative
variable
3. two or more categorical variables.
7. 1. TWO QUANTITATIVE VARIABLES
•Age and amount of interest in school
•Reading achievement and mathematics
achievement
•Classroom humanism and student
motivation
•Amount of time watching television and
8. 2. ONE CATEGORICAL AND ONE QUANTITATIVE VARIABLE
Method used to teach reading and
reading achievement
Counselling approach and level of
anxiety
Nationality and liking for school
Student gender and amount of praise
9. 3. TWO CATEGORICAL VARIABLE
Gender of teacher and subject
taught
Administrative style and college
major
Religious affiliation and political
10. You can usually identify the type
of variable by asking two
questions:
1.What type of data does the
variable contain?
2.What part of the experiment does
the variable represent?
11. A variable that contains
quantitative data is a quantitative
variable,
A variable that contains categorical
data is a categorical variable.
12. QUANTITATIVE VARIABLES
•When you collect quantitative
data, the numbers you record
represent real amounts that
can be added, subtracted,
divided, etc.
15. INDEPENDENT VARIABLES
-the one you think might be
the cause.
- Are those that the researcher
chooses to study in order to
assess their possible effects on
16. INDEPENDENT VARIABLES
- is presumed to affect
(atleast partly caused) or
somehow influence at least
one other variable.
19. Example
If you want to test whether some plant
species are more salt-tolerant than
others, some key variables you might
measure include the amount of salt you
add to the water, the species of
plants being studied, and variables
related to plant health
like growth and wilting.
23. CATEGORICAL VARIABLES
- represent groupings of some
kind. They are sometimes
recorded as numbers, but the
numbers represent categories
rather than actual amounts of
things.
24. VARIABLE
- Is a characteristic of an
individual or organization that
can be observed and
measured, it can vary among
people of organizations and
studies.
25. PRIMARY KINDS OF VARIABLES:
1.Independent variable
2.Dependent variable
3.Intervening or mediating
variable
4.Control variable
5.Confounding variable
26. 1. INDEPENDENT VARIABLE
-Variables you manipulate in order to affect
the outcome of an experiment.
-Those that cause, influence or affect
outcomes.
-They are invariable called treatment,
manipulated, antecedent or predictor
variables.
28. 2. DEPENDENT VARIABLE
-Variables that represent the outcome
of the experiment.
-Those that show the effects or results
or outcomes of the influence of the
independent variables.
-Also known as response variables
30. 3. INTERVENING OR MEDIATING
VARIABLE
--Those that are in-between the
independent and dependent
variables, that is, showing the
effects of the independent
variable on the dependent
31. 4. CONTROL VARIABLE
- Those that are measured in a
study because they potentially
influence the dependent variable,
using statistical procedures like
analysis or co-variance to control
these variable.
33. 5. CONFOUNDING VARIABLE
-Those that are not actually
measured but they exist.
-A variable that hides the true
effect of another variable in
your experiment.
35. CASE 1
Andrew notices that his shower head is covered by
a strange green slime. His friend Bart tells him that
coconut juice will not get rid of the green slime.
Andrew decides to check this out by spraying half
of the shower head with coconut juice. He sprays
the other half of the shower head with water. After
3 days od “treatment” there were no changes in
the appearance of the green slime on either side of
the shower head.
36. ANSWER THE FOLLOWING
1.What is being tested in the scenario?
What kind of variable is this?
________________________________________________________________________________
2. What is the effect of the treatment
used? What kind of variable is this?
_____________________________
37. CASE 2
Brian believes that mice exposed to microwaves
will become extra strong (maybe he’s been reading too
much Radioactive Man). He decides to perform this
experiment.
He places 10 mice in a microwave for 10 seconds.
He places another 10 mice in a microwave for 5
seconds. Lastly, he has 10 mice that have not been put
in the microwave.
For his test he placed a heavy block of wood in
