1. Causal Comparative
Research(ex post facto)
What is it ?

2. Causal Comparative
Research
Determine the cause of existing
differences among groups.
The AIM

3. Causal Comparative
Research
 At least two different groups are
compared on a dependent variable or
measure of performance (called the
“effect”) because the independent
variable (called the “cause”) has already
occurred or cannot be manipulated.
 Dependent variable-the change or
difference occurring as a result of the
independent variable.
 Independent variable- an activity of
characteristic believed to make a
difference with respect to some behavior.

4. Causal Comparative
Research
 The researcher attempts to determine the
cause, or reason, for pre existing differences
in groups of individuals.
 Attempts to identify cause and effect
relationships.
 Involve two or more group variables.
 Involve making comparison.
 Individuals are not randomly selected and
assigned to two or more groups.
 Cannot manipulate the independent variable
 Less costly and time consuming

5. Causal Comparative
Research
Type 1 Type 2 Type 3
• Exploration of • Exploration of • Exploration of the
effects (dependent causes consequences
variable) causes by (independent (dependent
membership in a variable) of a group variable) of an
given group. membership. intervention.
• Question: What • Question: What • Question: How do
differences in causes individuals students taught by
abilities are caused to join a gang? the inquiry method
by gender? react to
propaganda?

6. Causal Comparative
Research
1. Problem
2. Sample
STEPS
Taken 3. Design and
Procedure
4. Data Analysis

7. Causal Comparative
Research
Example: The Relationship between Years of Experience and
Job Satisfaction
Causal Comparative Design
 Hypotheses
• Alternative- Teachers with a high level of experience will be more
satisfied with their jobs than teachers with low levels of experience.
• Null- Teachers with a high level of experience will be equally satisfied
with their jobs when compared to teachers with low levels of
experience.
 Variables
• Dependent- Job satisfaction
• Independent- Years of experience
• Two levels (high & low)
• Exists naturally in the population of teachers at the start of study.

8. Causal Comparative
Research
Example: The Relationship between Years of Experience and
Job Satisfaction
Causal Comparative Design (cont.)
 Sample
• Two groups sampled, one for each level of the independent variable
• High Experience
• Low Experience

9. Causal Comparative
Research
Example: The Relationship between Years of Experience and
Job Satisfaction
Causal Comparative Design (cont.)
 Design and Procedure
• Select two groups that differ on some independent variable
• One group possesses some characteristic that the other does not
• Each group possesses the characteristic but in differing amount
• The independent variable must be clearly operationally defined
* Randomly sample subjects from each of the two groups
• Collect background information on subjects to determine the equality of
the groups
• Compare groups on the dependent variable

10. Causal Comparative
Research
Example: The Relationship between Years of Experience and
Job Satisfaction
Causal Comparative Design (cont.)
 Design and Procedure
Control of Extraneous variable
• What other variable besides years of experience could explain job
satisfaction among teachers?
• Matching: Each subject in the high experience group is matched with a
subject with a low experience group along the variable of class size.
• Each high experience teacher who teachers a large class is matched
with a low experience teacher who teaches a large class.
• Each high experience teacher who teaches a small class is matched
with a low experience teacher who teaches a small class.

11. Causal Comparative
Research
Example: The Relationship between Years of Experience and
Job Satisfaction
Causal Comparative Design (cont.)
 Data Analysis
• Mean- job satisfaction ratings for High Experience and Low Experience
subjects are compared using t-test, ANOVA or other appropriate
statistical test.
• Rejection of the null hypothesis supports the alternative hypothesis that
years of experience result in increased job satisfaction.

12. Causal Comparative
Research
Finding:
People with
lung cancer
Example: smoke more
Conclusion: Caution: A
than people
What without lung Smoking is third
causes cancer. There a possible factor?
are no other cause of
lung differences in
Proper
lung cancer.
cancer? lifestyle matching?
characteristics
between the
groups.

13. Causal Comparative
Research
More Examples of Causal
Comparative Research
• A researcher measured the mathematical
reasoning ability of young children who
had enrolled in Montessori schools and
compared the scores with a group of
similar children who had not been to
Montessori schools.
• A researcher measured the frequency of
students’ misbehavior at schools which
use corporal punishment and compared
that to schools which did not use corporal
punishment.

14. Causal Comparative
Research

15. Causal Comparative
Research

16. Causal Comparative
Research

17. Causal Comparative
Research