Appraising scientific evidence: qualitative versus quantitative research
Medical knowledge is derived from a combination of qualitative and quantitative research. Qualitative research refers to the use of non-numerical observations to answer "Why?" questions, while quantitative methods use data that can be counted or converted into numerical form to address "How?" questions. As summarized in Table 5.2, each approach serves a different purpose, so most researchers view the two as complementary and accept a "mixed methods" approach.
Table 5.2: Comparison of qualitative and quantitative research methods
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Qualitative research
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Quantitative research
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Generates hypotheses
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Tests hypotheses
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Is generally inductive (works from the particular instance to the general conclusion)
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Is generally deductive (works from the general theory to the particular explanation)
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Focuses on studying the range of ideas; sampling approach provides representative coverage of ideas or concepts
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Focuses on studying the range of people; sampling provides representative coverage of people in the population
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Answers "why?" and "what does it mean?" questions
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Answers "what?", "how much?" and "how many?" questions
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Captures rich, contextual, and detailed information from a small number of participants
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Provides numeric estimates of frequency, severity, and associations from a large number of participants
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Example of a study question: What is the experience of being treated for breast cancer?
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Example of a study question: Does treatment for breast cancer reduce mortality and improve quality of life?
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Source:
”Appraising Scientific Evidence: qualitative versus quantitative research.” AFMC Primer on Population Health, The Association of Faculties of Medicine of Canada Public Health Educators’ Network, http://phprimer.afmc.ca/Part2-MethodsStudyingHealth/Chapter5AssessingEvidenceAndInformation/Appraisingscientificevidencequalitativeversusquantitativeresearch (Accessed September 17, 2015). License: Creative Commons BY-NC-SA
