Choose your qualitative study

Darshini Ayton

Each qualitative research design has a unique focus and will elicit different results. Hence, to facilitate the integration of qualitative research into health and social care, an understanding of these designs and what they can achieve is needed.

Table S2 presents an overview of considerations for each of the six qualitative study designs covered in section 2. The first column, on the far left, is a prompting question based on the key concept for the specific research design, and the answers to this question prompt are mapped to a corresponding research design (the column on the far right of the table).1,2 The second column indicates the practicalities of data collection, sample size, and time, resources and expertise required. Note that the sample sizes given are not prescriptive; they provide a guide or recommendation as to the likely number of participants required; for example, to inform applications for grants and ethics approval. The final column indicates the appropriate qualitative research design, based on all of these prior considerations. For more detail on each of the study designs, please read the corresponding chapter indicated in the final column.

Table S2. Considerations to inform the selection of a research design

Prompting question based on key concept Data collection Sample size Time, resources and expertise Qualitative study design
Do you want to describe a phenomena (situation) – who what, where? Semi-structured interviews; may require other forms of data collection, such as focus groups and observations. Small sample size, conveniently and purposively sampled. This will depend on the research question and context.

Recommended sample sizes: 3–20 interviews or 1–2 focus groups of 4–6 participants.3
Suitable for use by novice and busy researchers; can be embedded within mixed-methods studies. Descriptive study.

(Chapter 5)
Do you want to focus on the lived experience of individuals? In-depth interviews; typically does not involve focus groups. Small sample size, depending on whether the group is heterogeneous or homogenous, research question and context.

Recommended sample size of about 20 participants. 4
Expertise is required due to the complexity of understanding the different philosophical and methodological influences. Phenomenology.

(Chapter 6)
Do you want to create, implement and evaluate change or action in collaboration with members of a community or setting? Members of the community or setting must be involved in data collection and/or analysis.

Multiple forms of data collection are required: interviews, focus groups, surveys, existing data sources.
The sample size needed can be large due to the different cycles of action research; depends on the number of stakeholders and the research context. The sample size required may be similar to that of a case study Engaging with community members or stakeholders can take time and may require multiple rounds of engagement Action research.

(Chapter 7)
Do you want to study phenomena within context? Multiple forms of data collection are required: interviews, focus groups, surveys, existing data sources. If a multiple case study design – the sample size can be large due to having representatives from different stakeholder groups.

Recommended sample size is 30-100. 4
Multiple case studies can be resource-intensive and time-intensive. Case study.

(Chapter 8)
Are you interested in studying group behaviours, attitudes and experiences where culture is relevant (e.g. power, hierarchy, social norms, socio-cultural factors)? Participant observation which incorporates informal conversations, formal interviews, document analysis and direct observations. Moderate to large, depending on the size of the culture-sharing group. Recommended sample size of between 50-150.4 Time-intensive, requiring personnel for observations, interviews and analysis. Ethnography.

(Chapter 9)
Do you want to develop an explanation of processes or concepts through theory or a framework? Multiple forms of data collection – interviews, focus groups, surveys, existing data sources Tends to require a large sample size to achieve theoretical saturation, whereby domains of the theory are explored sufficiently across participants.

Of 10 grounded theory studies, the mean sample was 59. Studies in health sciences ranged from 20–147 participants. 4
Time-intensive, not suited to the novice researcher unless supervised by an experienced qualitative researcher Grounded theory.

(Chapter 10)
  1. Morse JM. The paradox of qualitative research design. Qual Health Res. 2003;13(10):1335–1336. doi:10.1177/1049732303258368
  2. Creswell J, Hanson W, Clark Plano V, Morales A. Qualitative research designs: selection and implementation. Couns Psychol. 2007;35(2):236–264. doi:10.1177/0011000006287390
  3. Magilvy JK, Thomas E. A first qualitative project: qualitative descriptive design for novice researchers. J Spec Pediatr Nurs. 2009;14(4):298–300. doi:10.1111/j.1744-6155.2009.00212.x
  4. Guetterman TC. Descriptions of sampling practices within five approaches to qualitative research in education and health sciences. Forum Qual Soc Res. 2015;16(2):25. Accessed July 4, 2023.