Community medicine chapters
Qualitative and mixed-methods research
What qualitative research is and how it differs from quantitative research, its main approaches (participatory action research, phenomenology, case study, grounded theory and ethnography), data collection and analysis methods, quality criteria, and mixed-methods designs.
- Qualitative research explores why and how people think and behave, using words rather than numbers: in-depth interviews, focus groups and observation, with purposive sampling until saturation.
- Main approaches: phenomenology (lived experience of a phenomenon), grounded theory (building a theory from the data), ethnography (culture of a group, by participant observation), case study (in-depth study of one case or setting), participatory action research (communities take part to bring change).
- Mixed methods combine quantitative and qualitative data in one study to answer questions neither can answer alone.
On this page
Overview
Quantitative research counts and measures ("how many?"). Qualitative research explores meanings, experiences, beliefs and behaviour ("why?" and "how?") in people's own words.
In community medicine, qualitative research explains, for example, why mothers refuse polio drops, why patients stop TB treatment, or how women decide where to give birth.
Qualitative vs quantitative research
| Feature | Quantitative | Qualitative |
|---|---|---|
| Question | How many? How much? Is there a difference? | Why? How? What is it like? |
| Data | Numbers | Words, images, observations |
| Approach | Deductive: tests hypotheses | Inductive: builds understanding and ideas from data |
| Sampling | Random, large, representative | Purposive, small, information-rich |
| Tools | Structured questionnaires, measurements | In-depth interviews, focus groups, observation |
| Analysis | Statistics | Thematic or content analysis (coding) |
| Result | Generalisable figures | Deep understanding of a context |
| Researcher's role | Detached | Engaged; reflexivity about own influence |
Main qualitative approaches
| Approach | Focus | Typical method | Example |
|---|---|---|---|
| Phenomenology | The lived experience of people who share a phenomenon; what it is like | In-depth interviews | What is it like to live with thalassaemia major? |
| Grounded theory | Generating a new theory grounded in the data | Interviews; constant comparison; theoretical sampling | Building a theory of how patients decide to seek care for TB |
| Ethnography | The culture, beliefs and practices of a group | Participant observation over a long time; field notes | Living in a village to understand birth practices |
| Case study | In-depth study of one case (a person, clinic, programme or event) in its real-life context | Multiple sources: interviews, documents, observation | How one district achieved high immunisation coverage |
| Participatory action research | Researchers and community members work together to solve a problem and bring change | Cycles of plan, act, observe, reflect | A community designing its own solution to open defecation |
Phenomenology = lived experience. Grounded theory = builds theory. Ethnography = culture, participant observation. Action research = participation and change.
Grounded theory starts without a hypothesis and ends with a theory. Quantitative research starts with a hypothesis and tests it.
Data collection methods
- In-depth interviews: one-to-one, open-ended, often semi-structured; explore personal experiences.
- Focus group discussions (FGDs): about 6–10 similar participants discussing a topic with a moderator; show shared views and group norms.
- Key informant interviews: people with special knowledge (for example community leaders, lady health workers).
- Observation: non-participant or participant observation.
- Document review and visual methods.
Sampling
- Purposive sampling: choosing participants who can give rich information on the topic.
- Snowball sampling: participants refer others (useful for hidden groups).
- Theoretical sampling: in grounded theory, choosing participants to test developing ideas.
- Data collection continues until saturation: no new themes appear.
Saturation is the point at which new interviews add no new information or themes.
Analysis
Interviews are recorded, transcribed, read repeatedly and coded. Codes are grouped into themes (thematic analysis). Grounded theory uses open, axial and selective coding with constant comparison.
Quality in qualitative research (trustworthiness)
| Criterion | Similar quantitative idea | Ways to achieve it |
|---|---|---|
| Credibility | Internal validity | Prolonged engagement, triangulation, member checking |
| Transferability | External validity | Thick description of the setting |
| Dependability | Reliability | Audit trail |
| Confirmability | Objectivity | Reflexivity, audit trail |
Triangulation: using more than one method, data source, investigator or theory to cross-check findings.
Mixed-methods research
Mixed methods combine quantitative and qualitative data in one study, so the strengths of one balance the weaknesses of the other.
| Design | How it works |
|---|---|
| Convergent (parallel) | Collect both types at the same time; compare and merge results |
| Explanatory sequential | Quantitative first, then qualitative to explain the numbers (for example a survey shows low vaccine uptake; interviews explain why) |
| Exploratory sequential | Qualitative first to explore, then quantitative to test or measure (for example interviews to develop a questionnaire, then a survey) |
Expect: qualitative vs quantitative (inductive vs deductive), the five approaches with a matching example (phenomenology, grounded theory, ethnography, case study, participatory action research), in-depth interviews vs focus groups, purposive sampling, saturation, triangulation and the types of mixed-methods design.
Quick revision
- Qualitative: why and how; words; inductive; purposive sampling; saturation.
- Phenomenology: lived experience. Grounded theory: builds theory.
- Ethnography: culture; participant observation. Case study: one case in depth.
- Participatory action research: community as co-researchers; plan, act, observe, reflect.
- Focus group: 6–10 people. Triangulation: several sources or methods.
- Mixed methods: convergent, explanatory sequential, exploratory sequential.
Written by The House Job from Excel Community Medicine and Park's Textbook of Preventive and Social Medicine (named in the UHS PGET syllabus), with standard research methods references.
FAQ
What is phenomenological research?
A qualitative approach that studies the lived experience of people who share a particular phenomenon.
What is grounded theory?
A qualitative approach that develops a new theory from the data through constant comparison, rather than testing an existing hypothesis.
What is data saturation?
The point in qualitative data collection when new interviews or observations no longer produce new themes.
What is mixed-methods research?
Research that combines quantitative and qualitative data collection and analysis in a single study.