Types of Research: An Overview of Quantitative and Qualitative Approaches

1. Types of Research:An Overview of Quantitative and Qualitative Approaches Drs. Dodge & Pruett 1/31/06

2. 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.

3. 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”.

4. Research Perspectives Cont. • Quantitative Research • generally stems from a positivist tradition • Qualitative Research • generally follows the phenomenological tradition

5. 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).

6. 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.

7. 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;

8. Types of Quantitative Research Cont. • Descriptive studies, which can include: • simple, quantitative description of groups or phenomena (e.g., means and standard deviations on number of relevant variables) • reduction of descriptive data to underlying factors or dimensions (e.g., factor analysis, multidimensional scaling); and • 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).

9. 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.

10. 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.

11. 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)

12. Quantitative vs. Qualitative 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

13. 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: Design

14. 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!

15. 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!