Are you wondering what quantitative research design is best for your thesis/dissertation? This webinar will present several options and criteria to choose the most appropriate one. The topics are: * Characteristics of Quantitative Research * When to Choose Quantitative Research * Types of Quantitative Research Designs * Description, Basic Diagram, and Threats to Validity of Each Type of Design

1. Thanks for Coming
We will start in just a moment

2. How to Know if a
Quantitative Research
Design Is Appropriate for
Your Thesis

3. Taken from: Wiersma, W. & Jurs, S.G. (2009). Research methods in education: An
introduction (9th ed.). Boston, MA: Allyn and Bacon
Characteristics of Quantitative Research
• Deductive
• Look for relationships, effects, causes
• Theory-based
• Focused on individual variables
• Context- free (Generalizations)
• Detached role of researcher
• Statistical analysis
(Wiersma
&
Jurs,
2009,
p.
15)

4. When to Choose Quantitative Research
If you are interested in:
• Determining relationships, effects, and/or
causes
• Testing theories, models, approaches (even if
that is not an explicit goal of the study, but
theoretical principles are important in one way
or another)

5. Types of Quantitative Research
Designs
• Pre-experimental: Little or no control
• Experimental: High degree of control
• Quasi-experimental: Minor level of control
because random selection or assignment is not
possible. Statistics is used to improve the
control of variables

6. Pre-Experimental Designs
• Case study
• One group pretest –
posttest
• Static group comparison or
cross-sectional

7. Case Study Design
• Description: One group is studied after applying a
treatment or intervention
• Diagram: X O2 X = Treatment O2 = Posttest
• Threats to validity: Little or no control of the effect of
variables, history, maturation, selection, mortality, and
interaction effects of selection biases and the
experimental treatment

8. One Group Pretest-Posttest Design
• Description: The dependent variable is measured, the
treatment or intervention is applied, and the dependent
variable is measured again
• Diagram: O1 X O2 O1 = Pretest X = Treatment O2 = Posttest
•
Threats to validity: History, maturation,
instrumentation, mortality, selection- maturation
interaction, reactive effect of testing, and interaction
effects of selection biases and the experimental
treatment

9. Static Group Comparison or Cross-
Sectional Design
• Description: A group to which a treatment has been
applied is compared to another group that has not
experienced it
• Diagram: X O2 X = Treatment O2 = Posttest
-­‐-­‐
O2
•
Threats to validity: Selection, mortality, reactive
effect of testing, and interaction effects of selection
biases and the experimental treatment

10. Experimental Designs
• Randomized posttest groups
• Pretest- posttest control group
• Solomon four groups
• Factorial

11. • Descrip(on:
Two
groups
are
compared
using
pos@est
and
random
assignment
of
subjects
and
treatment
to
control
prior
differences
• Diagram:
R
X
O2
R = Randomization X = Treatment O2 = Posttest
R
-­‐
O2
• Threats
to
validity:
The
change
of
the
experimental
group
cannot
be
measured
Randomized Posttest Groups Design

12. • Description: Two groups are compared using pretest
and posttest and random assignment of subjects and
treatment
• Diagram: R O1 X O2 R = Randomization O1 = Pretest X = Treatment O2 = Posttest
R O1 - O2
• Threats to validity: Reactive effect of testing
Pretest –Posttest Control Group
Design

13. • Description: To address the reactive effect of testing,
two control groups are added to the pretest-posttest
control group design; one without taking pretest and
another one without pretest and treatment
• Diagram: R O1 X O2
R O1 - O2
R - X O2
R - - O2
R = Randomization O1 = Pretest X = Treatment O2 = Posttest
• Threats to validity: None by itself
Solomon Four Groups Design

14. • Descrip(on:
The
different
levels
of
two
or
more
independent
variables
(factors)
are
considered
to
establish
not
only
their
effects
on
the
dependent
variable
but
also
the
ones
caused
by
the
interacMon
among
them
• Diagram: R X11 O (Notation of a 2 X 2 factorial design)
R X12 O
R X21 O
R X22 O
R = Randomization X11 = Factor 1, level 1 X12 = Factor 1, level 2 X21 = Factor 2, level 1 X22 = Factor 2, level 2 O =
Measurement
• Threats
to
validity:
None
by
itself
Factorial Design

15. Quasi-Experimental Designs
• Nonrandomized pretest-posttest control group
• Counterbalanced
• Time series

16. • Description: Two groups are compared using pretest
and posttest. There is not random assignment of
subjects since they are already in groups
• Diagram: O1 X O2 O1 = Pretest X = Treatment O2 = Posttest
O1 - O2
• Threats to validity: Selection, statistical regression,
and reactive effect of testing
Non Randomized Pretest –Posttest
Control Group Design

17. • Description: The order in which treatments are
administrated is changed during the study so as to test
every subject for all the considered conditions
• Basic Diagram :
G1 XA XB O
G2 XB XA O
X = Treatment G = Group O = Measurement
• Threats to validity: Multiple treatment interference
Counterbalanced Design

18. • Description: The dependent variable is measured
several times before applying a treatment and then a
new series of measurement is performed
• Diagram : O1 O2 … X Oi… On
X = Treatment O = Measurement
• Threats to validity: History and reactive effect of
testing
Time Series Design

19. Now you know: Any question?
1. Characteristics of
quantitative
research
2. When to choose
quantitative
research
3. Types of quantitative
research designs
4. Description, basic
diagram, and threats
to validity of each
type of design

20. February is Coaching Month
• Each week will introduce and focus on a different coach
• Lots of new helpful hints per phase of doctoral work
• Additional videos in the interviews
• Ask questions during webinars
• Members have professors on Skype
I invite you to read:
My professor hints about coaching at
http://doctoralnet.com/maria.html
The challenges of each phase at:
http://doctoralnet.com/starting-phd-research/phase-1-files/professor-
hints/item/825-maria-sanchezphase1.html (phase 1)
http://doctoralnet.com/beginning-to-write-phd-thesis/professor-hints-
phase-2/item/827-maria-sanchezphase2.html (phase 2)
http://doctoralnet.com/finishing-phd-thesis/professor-hints-phase-3/
item/828-maria-sanchezphase3.html (phase 3)
And my interview at
http://doctoralnet.com/home/about-us/interview-with-prof-maria-
sanchez-patino.html

21. What’s Up 4 Free @ DoctoralNet.com?
1. Community
2. Blog
3. 365
Daily
InspiraMons
4. Your
personal
milestone
checklist
–
free
but
requires
site
basic
registraMon
5. Want
these
slides?
Ask
for
them
at
maria@doctoralnet.com