Causal Comparative Research.ppt

Causal Comparative Research Design

1. CAUSAL-COMPARATIVE
RESEARCH

2. OBJECTIVES
•Explain what is meant by the term “causal-comparative
research.”
•Describe how causal-comparative research is both similar to
and different from both correlational and experimental
research.
•Identify and describe the steps involved in conducting a
causal-comparative study.
•Look at a diagram of a design for a causal-comparative study.
•Describe some of the threats to internal validity that exist in
causal-comparative studies and discuss how to control for
these threats.
•Recognize a causal-comparative study when you come
across one in the educational research literature.

3. What is causal-comparative
research?
•Also known as “ex post facto” research. (Latin for
“after the fact”).
•In this type of research investigators attempt to
determine the cause or consequences of
differences that already exist between or among
groups of individuals.

4. In other words…
•Causal-comparative research is an attempt to
identify a causative relationship between an
independent variable and a dependent variable.
•The relationship between the independent variable
and dependent variable is usually a suggested
relationship (not proven) because you (the researcher)
do not have complete control over the independent
variable.

5. You are a first year agricultural education teacher at the local
high school. At the state CDE contest you run into a Billy
Bob (a fellow agricultural education teacher). When Billy
asks how your year is going, you tell them that you are
discouraged because your students do not seem to like your
teaching very much and complain about your style of testing.
Billy Bob tells you that they have been using e-moments and
some of the concepts from the FFA Life Knowledge
materials to teach their classes. They think that their
students really enjoy their teaching and are learning more
because of it.
You wonder if Billy Bob’s approach would work for you…

6. •An appropriate way to approach this situation would be
with a causal-comparative study.
•You (the researcher) observe that 2 groups differ on some
variable (teaching style) and then attempt to find the reason
for (or the results of) this difference.
***Note that the difference has already occurred.***

7. Similarities to correlational research
•Both types of research are examples of
associational research:
•Researchers seek to explore relationships among variables.
•Both attempt to explain phenomena of interest.
Causal-Comparative
& Correlational

8. •Both seek to identify variables that are worthy of
later exploration
•Often provide guidance for later experimental studies.
•Neither allow the researcher to manipulate the variables.
•Both attempt to explore causation.
Similarities to correlational research

9. Differences
Causal-Comparative
•Typically compare 2 or more
groups of subjects
•Involves at least 1 categorical
variable.
•Analyzes data by comparing
averages or uses cross break
tables.
Correlational
•Requires a score on each variable
for each subject.
•Investigate 2 or more quantitative
variables.
•Analyzes data by using
scatterplots and/or correlation
coefficients.

10. Similarities to experimental research
•Both require at least one categorical variable.
•Both compare group performances to determine
relationships.
Causal-Comparative
& Experimental

11. Differences
Causal-comparative
•No manipulation of the variables.
•Provide weaker evidence for
causation.
•The groups are already formed, the
researcher must find them.
Experimental
•The independent variable is
manipulated.
•Provide stronger evidence for
causation.
•The researcher can sometimes
assign subjects to treatment
groups.

12. The steps…
•Problem Formulation
•Select the sample of individuals to be studied.
•Instrumentation-achievement tests, questionnaires,
interviews, observational devices, attitudinal
measures…there are no limits…

13. The design
•The basic design is to select a group that has the
independent variable and select another group of
subjects that does not have the independent variable.
•The 2 groups are then compared on the dependent
variable.

14. Internal Validity
•Usually 2 weaknesses in the research:
•Lack of randomization
•Inability to manipulate an independent variable
•Threats
•Oftentimes subject bias occurs
•Location
•Instrumentation
•Loss of subjects

15. Data Analysis
•Means and standard deviations (only if variables are
quantitative)
•T-test for differences between means.
•Analysis of covariance

16. Proceed with caution!!!
•The researcher must remember that demonstrating a
relationship between 2 variables (even a very strong
relationship) does not “prove” that one variable actually
causes the other to change in a causal-comparative study.

17. Examples
•Exploration of effects caused by membership in a given
group.
•Question: What differences in abilities are caused by gender?
•Hypothesis: Females have a greater amount of linguistic ability
than males.

18. Examples
•Exploration of causesof group membership.
•Question: What causes individuals to join a gang?
•Hypothesis: Individuals who are members of gangs have more
aggressive personalities than individuals who are not members
of gangs.

19. Examples
•Exploration of the consequences of an
intervention.
•Question: How do students taught by the inquiry
method react to propaganda?
•Hypothesis: Students who were taught by the inquiry
method are more critical of propaganda than are
those who were taught by the lecture method.

20. Example
•A Comparison of Urban Teacher Characteristics for
Student Interns Placed in Different Urban School Settings
•Classroom Behavior of Good and Poor Readers

21. Chapter in Book
•Chapter 16
•Pages 369 to 395
•Summary on pages 393 to 394

22. References
•Fraenkel, J. (2006). How to design and evaluate research in
education. (pp. 369-395). New York, NY: McGraw-Hill.
•McKinney, S. (2004). A comparison of urban teacher characteristics
for student interns placed in different urban school settings. The
professional educator, 26(2).
•Wasson, B. (2001). Classroom behavior of good and poor readers.
The professional educator, 23(3).
•www.mnstate.edu/wasson/ed603/ed603lesson12.htm
•www.faculty-staff.ou.edu/B/Nancy.H.Barry-1/cause.html