Data collection


To describe the different methods that are used in qualitative research and provide relevant literature for more information on these types of methods.

  • Field notes
  • Topic lists
  • Coding information for transcripts
Qualitative research methods

Different methods of data-collection are used in qualitative research. The most common are interviews, focus group discussions, observational methods and document analysis. A relatively new method is an art-based data-collection method. Combining two or more data collection methods, for instance interviews as well as focus groups (‘data triangulation’) enhances the credibility of the study. Irrespective of the data collection method applied, it is important to keep a diary during the study, with reflections on the process (e.g. regarding method and participant selection) and the role and influence of the researcher (‘reflexivity’).

Example using methodological triangulation:

  • Sewdas, R. et al. (2017) Why older workers work beyond the retirement age: a qualitative study. BMC Public Health, 17: 672.
    This study is based on a combination of semi-structured telephone interviews and focus groups.

Interviews are useful to explore experiences, views, opinions, or beliefs on specific matters. Transcripts of interviews can be explored and compared to others, to develop an understanding of the underlying structures of beliefs (See chapter 4 in Green & Thorogood, 2010). There are different grades of structuring the interview: structured, semi-structured or open/in-depth. Often the researcher develops a topic list before the start of the interview, which can be used in a flexible manner. As the interview is a product of interaction between the researcher and the interviewee, the setting and skills of the researcher are of importance (e.g. the ability to build a sense of trust (developing rapport), the way of phrasing questions, give the interviewee room to tell a story, (body language). Furthermore, it is important to think about the type of transcription of audio tapes. Finally, it may be important to make notes after each interview on the type of setting, non-verbal signals (body language) of an interviewee and other important things/events that may have happened during the interview and might play a role on the gathered data.


  • Bakker, M. et al. (2015) Need and value of case management in multidisciplinary ALS care: A qualitative study on the perspectives of patients, spousal caregivers and professionals. Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration, 16(3-4), 180-186.
  • Bakker, M. et al. (2016) Experiences and perspectives of patients with post-polio syndrome and therapists with exercise and cognitive behavioural therapy. BMC neurology, 16(1), 23-34.
  • Ockhuijsen, H.D.L. et al. (2014) Pregnancy After Miscarriage: Balancing between Loss of Control and Searching for Control. Research in Nursing & Health, 37, 267-275.
Focus group discussions

A focus group is a meeting where a group of people discuss a certain topic to examine their views/experiences on this particular topic. These discussions are useful to examine underlying reasons, motives, values and beliefs. The researcher stimulates discussion in order to examine how knowledge and ideas develop and operate in a given group. Most of the time, a facilitator guides a discussion about a particular topic in a group of usually 6-12 people. Some sensitive issues might be easier to discuss within a group, although other (personal) information might be withheld, for instance when persons are not acquainted with each other or because of hierarchical relations within the group. Therefore, a group of people need to have a certain homogeneity to be as comfortable as possible for discussing a certain topic within a group.

The role of the facilitator is to create an open atmosphere, involve participants in the discussion and manage this discussion. The organization of a focus group requires careful attention. This includes the sampling and recruitment of participants, the composition of the topic list and how the data will be collected. Each focus group has a unique design (a script instead of a topic list for an interview) that involve various exercises to stimulate discussion and reflection between participants. Exercises can also stimulate creative ideas and getting someone to tell a story.

Next to the facilitator, it might also be useful to include an observer. The observer could be useful for taking notes on non-verbal signs (body language), take notes of the most important things that have been said, support the facilitator in the discussion, and keep track of the time. In this way, the facilitator can concentrate on guiding the discussion.


  • Middelweerd, A. et al. (2015) What features do Dutch university students prefer in a smartphone application for promotion of physical activity? A qualitative approach. International Journal of Behavioral Nutrition and Physical Activity, 12: 31.
  • Pitts MJ, Adams Tufts K. (2013) ‘Implications of the Virginia human papillomavirus vaccine mandate for parental vaccine acceptance.’ Qualitative Health Research. 2013.
  • Tausch AP, Menold N. Methodological Aspects of Focus Groups in Health Research: Results of Qualitative Interviews With Focus Group Moderators Global Qualitative Nursing Research. 2016;3:1-12. DOI: 10.1177/2333393616630466
Observational methods

Observational methods are used to understand phenomena by studying people’s accounts and actions in an everyday context. There are different types of observations, with various degrees of research participation, like non-participating observation (e.g. by using video recordings), and participant observation or ethnography. Ethnography ‘usually involves the researcher participating, overtly or covertly, in people’s daily lives for an extended period of time, watching what happens, listening to what is said, and/or asking questions through informal and formal interviews, collecting documents and artefacts’ (Hammersley & Atkinson, 2007: 3).

Observations are focused on gaining an in-depth understanding of a specific context. Observations can, just as interviews, be conducted at the continuum of open-ended and focused observations (Mortelmans, 2020). An “observation matrix” or “observation guide” is used to guide the observations. Observations are often conducted by one researcher who can build up relations with people in the field they are researching. Triangulation of researchers can contribute to the quality of the study, as it enables researchers to critically reflect upon their perspectives and how they make meaning of “the observed”. 


  • Pasman, H.R.W. et al. (2003) Feeding nursing home patients with severe dementia: A qualitative study. Journal of Advanced Nursing, 42, 3, 304-311.
    This paper is based on participant observation by two researchers in two Dutch nursing homes.
Document analysis

Document analysis is based on existing sources, like government reports, personal documents, articles in newspapers, medical curricula, books or medical records. Document analysis is often employed to conduct a discourse analysis or to conduct a policy analysis. Document analysis can also be done to support or inform other methods of data collection such as interviews or observations (i.e. data-triangulation).


  • Stuij, M. & Stokvis, R. (2015) Sport, health and the genesis of a physical activity policy in the Netherlands. International Journal of Sport Policy and Politics. 7 (2): 217-232.
    This paper is based on an analysis of policy documents and existing surveys on sport participation.
  • Muntinga, M. E., Krajenbrink, V. Q. E., Peerdeman, S. M., Croiset, G., & Verdonk, P. (2016). Toward diversity-responsive medical education: taking an intersectionality-based approach to a curriculum evaluation. Advances in Health Sciences Education21(3), 541-559.
    This paper is based on an analysis of medical curricula from an intersectional perspective.
Arts-based methods of data-collection

Arts-based methods of data-collection receive growing attention from qualitative health scholars (Mitchell et al, 2017). Arts-based methods allow participants in qualitative research to express their lived experiences in non-verbal ways, which can support an understanding of their lived experiences in other ways than interviews, focus groups of observations can do. One example of arts-based research is photovoice (Wang, 1997), which is increasingly often used in different groups such as children (Abma & Schrijver, 2020). Photovoice can be used alone, or in combination with interviews or focus groups (Sarti et al, 2019). 


  • Abma, T. A., & Schrijver, J. (2020). ‘Are we famous or something?’ Participatory Health Research with children using photovoice. Educational Action Research28(3), 405-426.
  • Sarti, A., Dedding, C., & Bunders, J. F. (2019). Beyond a deficiencies approach: Towards a more integral representation of the everyday life of children growing up in contexts of poverty. Qualitative Social Work18(5), 818-833.
  • Vaart, G. V. D., Hoven, B. V., & Huigen, P. P. (2018). Creative and arts-based research methods in academic research: Lessons from a participatory research project in the Netherlands. Forum: Qualitative Social Research, 19(2), 30.
Quality procedures

Devers (1999) formulated several strategies for enhancing the rigor of qualitative research:

Criteria Strategies
Credibility / Internal validity
  • Triangulation. The purpose of triangulation is to make use of multiple data sources, investigators, methods or theory to the extent possible to provide corroborating evidence.
  • Search for Disconfirming Evidence (“deviant” or “negative” cases). Instead of ignoring cases or information that “doesn’t fit”, the researcher actively looks for cases that do not fit the pattern and refines the theory and working hypotheses in light of this evidence. The researcher(s) continues this process until all cases fit, eliminating all outliers and exceptions.
  • Subject Review (Also called “member checking” and “dialogue with participants”). The researcher(s) solicits research “subject”, group member, or participant views of the credibility of interpretation and findings. In some cases, this strategy is also used to increase the probability that research results will be used.
Transferability / External validity
  • Detailed Description of the Context, i.e. the study context, the investigator’s role in the context and of how the context affects the ability to answer the original research question.
Dependability / Reliability
  • Data Archiving/Creating an Audit Trail. The researcher(s) should ensure the completeness and accuracy of documents (e.g. interviews, observations, etc.) and be clear about the coding schemes and data analysis process. Theoretically, this would allow someone not connected with the study to review the primary documents and coding schemes to assess whether the findings, interpretations, and conclusions are supported.
  • Skeptical Peer Review. A skeptical peer-reviewer plays the role of devil’s advocate, asking difficult questions about methods, meanings, and interpretation of the data. This process provides an external check on the research.
Confirmability / Objectivity
  • Triangulation. See description above.
  • Skeptical Peer Review or Audits. See above.
  • Search for Disconfirming Evidence or Negative Cases. See above.
  • Reflective Journal Keeping by the Researcher. Because the researcher is the research instrument in qualitative research, he or she should keep journal notes on how his or her personal characteristics, feelings, and biases that may be influencing the work and how he or she tries to manage them to the extent possible.
Documenting your Quality control procedures

To ensure proper data collection including quality control and change control procedures are applied, see Checklist Quality control procedures and have your DMP checked by a (research) data management consultant.

Responsibilities and ethics

It is important to carefully reflect on and think about ethical dilemmas related to the practice of qualitative research as well as responsibilities of the researchers, especially regarding respondents. Procedures related to informed consent, protecting the privacy of respondents often require additional reflection from researchers, for example when qualitative research is conducted in a specific setting (ethnographic research or case studies) and standard procedures such as pseudonimizing or encoding the data are not sufficient to ensure privacy. Also, the nature of qualitative research requires personal contact between researcher and researched, for example during interviews or observations. This can also yield dilemmas that cannot be anticipated upon with standard ethics procedures, but require moral reflection during the research process. Please consult the guideline on privacy. For specifics in a study, or contact the privacy officer /data protection officer and read into ‘procedural’ ‘situational’ and ‘relational ethics’ in qualitative research (e.g. Wijngaarden et al, 2018; Mortelmans, 2018).