Research Methods

00:00 Jan 01


Qualitative, Quantitative, and Mixed Methods Approach: Powlin V. Manuel MD, MBA

Approaches to research questions vary based on the nature of the question, the research problem being addressed, the source of data, the significance of the project, and purpose of the study. Research methods are qualitative, quantitative, and mixed methods.  In qualitative study the researcher identifies a single main phenomenon, mentions the strategy of enquiry, the participants, and research site; in quantitative study the researcher states the theory, the variables and their relationship and comparison (Creswell, 2009). Quantitative research may include experimental strategies of inquiry, and pre-and post-test measures of attitudes and represents the post-positive worldview; qualitative research is conducted, for example, through "ethnographic design" (p. 16) and observation of behavior and represents a constructivist worldview; the mixed method approach involves collection of both quantitative and qualitative data sequentially or concurrently, and embraces a pragmatic world-view.

Qualitative Research

Qualitative research is used to address Open-ended questions. After the problem is stated by the question researcher studies through literature, reviews all relevant published data, defines area of research that does not satisfactorily address certain aspects of the issues and defines the gap in existing knowledge, and thus defines the purpose of the study. In a qualitative method the statistical studies are described in general terms, but precise statistical values are not emphasized (Pan, 2004). If you take up a question T "what factors predict good marital communication?" it  is an open-ended question The strategy to find answer to this question is addressed by qualitative approach. Researchers use qualitative research as he or she collects participant's answers, focuses on a single concept such as this, studies the concepts at the settings of participants as could be done in this case. The researcher validates the accuracy of the findings. In qualitative research the researcher seeks the views of the participants. The qualitative research encompasses ethnography, the researcher studying the effect of culture on the problem studied. In addition findings are in contextual settings, involves views of participants in case studies, and consist of phenomenological research and narrative research (Creswell, 2009). The Janestick (2001) argues that qualitative research seeks to describe, explain, the familiar in a contextual, personal, and passion.

Qualitative research upholds a participatory worldview (Creswell, 2009) in the sense that it may change the lives of the participants such as in this issue in which case findings the factors that lead to good marital communication can lead to better family life and outcome. Statistical analysis can be conducted from the responses from participants as well as comparing the outcome of marriage based on the certain features which could be conducive to longer married life or otherwise.

Quantitative Research Method

To address the question for example of whether Medication is efficacious for treatment of adult adhd the researcher will use a quantitative research method. ADHD is a common disorder with a prevalence rate worldwide of 5.9% according to one report (Polanzyk, de-Lima, Horta, Biederman, & Rohde, 2007).  At least half of children with childhood ADHD continue to suffer from symptoms of the disorder as adults (Taman, Tuglu, & Ozcan, 2006). At least half of children with childhood ADHD continue to suffer from symptoms of the disorder as adults (Taman, Tuglu, & Ozcan, 2006). The data on the effectiveness of medical treatment on adult ADHD is scant as most of the research on this area has been conducted on children. There is a gap in knowledge and the question is a relevant question as the findings of the study could make a significant impact on the lives of the patients.            Quantitative approach could consist of experimental designs as well as non-experimental designs such as surveys. Quantitative researches can include true experiments and quasi experiments such as co-relational studies or specific single-subject experiments (Creswell, 2009). Survey results provide a quantitative description of attitudes of a population by studying a representative sample of the population, and can consist of cross-sectional and longitudinal studies using questionnaires or interviews for data collection. Experimental research is conducted to determine if a specific treatment influences an outcome.

In quantitative research after the question is identified, the study starts with recruiting the representative sample.  Experiments could include true experiments with random assignments of subjects to treatment conditions or quasi-mode experiments that use non-randomized designs. Sometime placebo is used to compare the effect with those of actual medication.  It will be considered a double-blind study as the experimenter will not know who is receiving the medication and the patients will not know whether he or she is receiving a medication or placebo at any specific time. The medication as well as placebo could be switched in the middle of the study and results compared at the end of the study. In this case it will be double blind crossover study. In this experiment questionnaires for adult adhd will be administered after informed consent. Medications and placebo are given for a period of three months and adhd questionnaires are re-administered by a staff member who will not know which group received medication or placebo. The medications and placebo are switched over and administered for another three months and adult ADHD questionnaires are re-administered. Efficacy needs to be defined before starting the study; in a quantitative method it could defined as improvement in ADHD scores. Or one could add quality of life indices as a whole as an additional measurement to define efficacy. That will be left to the researcher and the funds available to conduct the study. Often confounding factors can affect the result of the study; in which case we have to make accommodations to discount the effect of confounding factors such as co-morbid conditions such anxiety disorders. If the researcher wants to encompass confounding variables the number in the sample will have to be high enough to attain statistical significance.

Some authors argue that the delineation between qualitative and quantitative category for research need to be framed in terms of logic of the research methodologies (Howe, & Esenhart, 1990). Research community for some time held the conviction that only quantitative studies can provide evidence to make a claim, to learn about what works or not, for studies of knowledge to be value free or objective, and for authors to be not involved, but be separate. Recently qualitative methods have claimed the same position as quantitative methods to obtain same reliable and reproducible results. Many authors believe that mixed method approach will be more appropriate in certain situations. However according to some authors mixed method research is currently not in a position to provide perfect solution (Johnson, 2004). In the case of the study of adult adhd a mixed method could be appropriate also. We can study and understand by measuring the quantitative change in adhd scores and also do qualitative fields study by concerning the change in quality of life by questionnaires for qualitative finding in a combination research.


When quantitative studies derived from positivism insists on measuring and knowing, qualitative measures including phenomenology, studies the effect expressed through human experience in the social and cultural context. Irrespective of what method of inquiry we choose in a search for further knowledge as scholar practitioners we must continue with our change effort in order to translate psychological knowledge into knowledge that can be used by governments, communities, and individuals" (Schneider, 2009, p.373).


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