3. Definitions
Research design: the framework used to
conduct the research
Research method: data collection techniques
(e.g., document analysis, interview, survey)
3
4. Definitions
Quantitative research2,6:
Assumptions:
Reality - objective & singular
Researcher - independent from research
Research - value-free, unbiased
Research process – deductive (generate
hypotheses from theory), emphasize cause/effect,
isolation of variables, context-free, prediction,
generalizability
4
8. Definitions
Two broad categories of quantitative designs:
Non-experimental
Experimental
A major difference - validity of the designs7
Internal validity: extent design can identify causal
relationships & rule out alternate explanations of
relationships between variables
External validity: extent design allows conclusions
to generalize beyond the confines of study
8
9. Definitions
Non-experimental designs tend to be low in
internal validity but higher in external validity
Experimental designs tend to be high in internal
validity but lower in external validity
9
10. Non-experimental
Non-experimental designs:
Descriptive
Correlational
Descriptive designs5,7 - identify the
characteristics of a phenomenon
Describe the variable under investigation –
not examine relationships among variables
For example: LARSN needs assessment
(Hoffman, Meadows, & Martin-Gardiner,
2009) 10
11. Non-experimental
Correlational designs examine relationships
among variables under investigation1,5,7
Tend to examine relationships as they exist
Do not isolate & manipulate variables to
establish causal relationships as in
experimental research
11
12. Non-experimental
For example, Eron, Huesmann, Lefkowitz, &
Walder (1972) examined relationship
between preferences for violent television &
aggressive behaviour
12
13. Non-experimental
Cannot make causal statements with
correlational research1,5,7
Directionality problem (if X <-> Y, does X ->Y or
Y ->X)
Third variable problem (if X <-> Y, possible
X<-Z->Y)
13
14. Non-experimental
More complex correlational designs can
suggest direction of causality
E.g., Cross-lagged panel correlation design
Eron and colleagues (1972) – collected data
at grade 3 &13 and correlated variables
between years – found moderate correlation
between grade 3 preference for violent tv &
grade 13 aggressive behaviour
14
15. Non-experimental
In groups of 3, please discuss:
Research question you would be interested in
researching
Design of your research (i.e., descriptive or
correlational)
Data sources for that project
Research methods you would use
15
16. Experimental
Experimental designs:
Experimental
Quasi-experimental
Experiment1,3,5,7 - variable is systematically
manipulated (independent variable; IV) to
observe effect of manipulation on another
variable (dependent variable; DV)
16
17. Experimental
Experimental control1,3,5,7 – hold extraneous
variables constant in experiment to isolate
effect of IV on DV
For example, Hopkins & Wilson (2009)
17
18. Experimental
Common experimental design: pre-test/post-test
control group design1,3,5,7
Measure Exposure Measure
Before After
Treatment 01 X 02
Group
Control Group 03 04
18
19. Experimental
If change from pre- to post-test for treatment
group & not control group (or not as much),
change can be attributed to the treatment
(assuming proper experimental controls)
Controlling for extraneous variables1,3,5,7:
Participant differences: random assignment of
participants to treatment and control groups or
matching
Situational differences: hold situations constant
19
20. Experimental
Pre-test/Post-test Control Group7 – possible pre-
test influences treatment (threat to external validity)
Post-test only control design7:
Exposure Measure
After
Treatment X 01
Group
Control Group 02
20
21. Experimental
Post-test only control group – groups should
be same on DV before treatment because of
random assignment
Other threats to external validity for
experiments8:
Interaction effect of selection bias and treatment
Reactive effects of the experiment
21
22. Experimental
Quasi-experimental designs5,8: not true
experiments because the groups tend to be
naturally occurring not groups created by
researcher
Try to match participants and control for
situational variables as much as possible
22
23. Experimental
Common quasi-experimental design: pre-test/post-
test non-equivalent group design8
Measure Exposure Measure
Before After
Treatment 01 X 02
Group
Control Group 03 04
23
24. Experimental
Example: Haffie, Meadows, Dunn, & Graves
(2009)
quasi-experimental research higher in
external validity than experiments (reflect real
life more) but weaker in internal validity than
experiments (do not control for all extraneous
variables) 8
24
25. Experimental
In groups of 3, please discuss:
New research question you would be interested in
researching
Design of your research (i.e., experimental or quasi-
experimental)
Data sources for that project
Research methods you would use
25
27. References
1. Bordens, K. S. & Abbott, B. B. (2008). Research design and
methods: A process approach (7th ed.). Boston: McGraw-Hill.
2. Creswell, J. W. (1994). Research design: Qualitative and
quantitative approaches. Thousand Oaks, CA: Sage Publications.
3. Elmes, D. G., Kantowitz, B. H., Roediger III, H. L. (1999).
Research methods in psychology (6th ed.). Pacific Grove, CA:
Brooks/Cole Publishing Company.
4. Eron, L. D., Huesmann, L. R., Lefkowitz, M. M. & Walder, L. O.
(1972). Does television violence cause aggression? American
Psychologist, 27, 253-263.
27
28. References
5. Leedy, P. D., & Ormrod, J. E. (2001). Practical research: Planning
and design (7th ed.). Upper Saddle River, N.J.: Merrill Prentice
Hall.
6. O'Leary, Z. (2004). The essential guide to doing research. London:
Sage.
7. Powell, R. R., & Connaway, L. S. (2004). Basic research methods
for librarians (4th ed.). Westport, Conn.: Libraries Unlimited.
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