Types of Research:
An Overview of Quantitative
and Qualitative Approaches
Drs. Dodge & Pruett
1/31/06
Observing Behavior
• Behavior in research can be observed or
measured.
• Because behavior varies so much, it is
critical that scientists have numerous ways
to measure and observe behavior in both
experimental and non-experimental
settings.
Research Perspectives
• According to Taylor and Bogdan (1984), two
major theoretical perspectives underlie much of
social science research. They are:
– a. the positivist tradition, which “seeks facts or
causes of social phenomena apart from the subjective
states of individuals” (Taylor & Bogdan, 1984, p. 1),
– b. the phenomenological perspective, which “is
committed to understanding social phenomena from
the actor’s own perspective”.
Research Perspectives Cont.
• Quantitative Research
– generally stems from a positivist tradition
• Qualitative Research
– generally follows the phenomenological
tradition
Research Perspectives
• Note that an operative word in the previous description
of both types of research was “generally.”
• Much of quantitative research is devoted to testing
theories, although theories are never really proven. They
are only accorded varying degrees of confirmation
(Campbell & Stanley, 1963; Cook & Campbell, 1979).
• In contrast “most qualitative studies are directed toward
developing or verifying theory” (Taylor & Bogdan, 1984,
p. 125). Qualitative research uses inductive reasoning
and flexible design to “develop concepts, insights, and
understanding from patterns in the data, rather than
collecting data to assess preconceived models,
hypothesis, or theories.” (Taylor & Bogdan, 1984, p. 5).
Quantitative Research
• Quantitative research: Collecting and reporting
observations numerically.
• The researcher may use questionnaires, tests,
and other measures to record frequency of
behavior, occurrence of behavior and/or duration
of behavior.
• After data is collected, it is analyzed statistically.
• Example: The mean GPA of students who work
over 20 hours a week is .50 points lower than
students who do not.
Types of Quantitative Research
• Experimental studies, which evaluate the effectiveness
of treatments or interventions through random
assignment of participants to treatment and control
groups; [Note that random assignment to groups is
different from random selection or random sampling.
Random sampling does not necessarily imply an
experimental design!];
• Quasi-experimental studies, which compare group
responses to an intervention when the participants were
not randomly assigned to groups but some measures of
individual differences are considered;
• Ex post facto or Correlational studies, which examine
existing relationships or differences among variables;
Types of Quantitative Research
Cont.
•
•
Descriptive studies, which can include:
1. simple, quantitative description of groups or
phenomena (e.g., means and standard deviations
on number of relevant variables)
2. reduction of descriptive data to underlying factors or
dimensions (e.g., factor analysis, multidimensional
scaling); and
3. some types of survey research.
Time series or Single subject research, which involves
in-depth quantitative study of the reaction of an
individual or a group of individuals to an intervention
(Szymanski, 1993).
Qualitative Research
• Qualitative Research: Data is collected
from observations and interviews. Can be
conducted in a lab or in the field.
• The qualitative approach yields data often
expressed in non-numerical terms using
language and images.
• The qualitative approach could include
summaries of discussions, interviews, and
video- or audio-taping of behaviors.
Qualitative Cont.
• A qualitative description of observations
may focus on patterns and themes that
emerge from language or images (i.e.,
Grounded Theory) .
• Example: A common theme that emerged
from talking to the students was that they
needed to work and would continue to do
so even if their grades suffered.
Types of Qualitative Research
• Ethnographies, in which the research studies an
intact cultural group in a natural setting during a
prolonged period;
• Case studies, in which the researcher explores a
single entity or phenomenon (‘the case’)
bounded by time and activity ; and
• Phenomenological studies, in which human
experiences are examined through the detailed
descriptions of the people being studies.
(Creswell, 1994, pp. 11-12)
Quantitative vs. Qualitative
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Quantitative Research
positivistic
Hypotheses/deductive
particularistic
objective/outsider centered
outcome oriented
natural science worldview
attempt to control variables
goal: find facts & causes
static reality assumed;
relative constancy in life
verification oriented
confirmatory
Qualitative Research
• phenomenological
• inductive
• holistic
• subjective/insider centered
• process oriented
• anthropological worldview
• relative lack of control
• goal: understand
participant's view
• dynamic reality assumed;
"slice of life"
• discovery oriented
• explanatory
Quantitative vs. Qualitative: Design
Quantitative
ResearchDesigns:
Experimental
Quasi-Experimental
Ex post facto
Correlational
Descriptive
Time Series/Single
Subject
Qualitative
Research Designs:
Ethnographic
Grounded theory
Case study
Phenomenological
Historical
Philosophical
Quantitative vs. Qualitative: Theory
• Although it was stated that quantitative research is
generally theory testing as opposed to theory generating,
some quantitative research (e.g., factor analysis), can
also be used to generate hypotheses and develop theory
(Rosenthal & Rosnow, 1984).
• To further complicate matters, quantitative research
techniques can be classified as explanatory or
predictive. This classification has implication for the
choice of statistical procedures and for the interpretation
of results (Pedhazur, 1982).
• The moral of the story is that research is inquiry into
complex phenomena; types of research, therefore,
cannot easily be classified into simple, mutually
exclusive categories!
Quantitative vs. Qualitative: Summary
• Neither is superior to the other
• Choosing one or the other is based on what is
needed in your study
– Hard stats that test a theory or support a
hypothesis
– Info about personal experiences of those
undergoing a new treatment
• High quality research projects may incorporate
aspects of both approaches! See Creswell
(2003). This book is an excellent resource!