Sample selection in quantitative research requires calculating a standard error, which is not possible for qualitative research. If it were, you would find that typical sample sizes in qualitative research (e.g., under 20) produce such wide confidence intervals that the estimates are of very little value.

So, even if you were to draw a random sample, it would be a waste of time. Instead, use a purposive sample to concentrate on hearing from the most relevant participants

In qualitative research, selecting a sample size involves several key criteria:

Purpose of the Study: The sample size should be sufficient to achieve the study's objectives and provide rich, detailed insights. For exploratory or descriptive research, smaller samples may be adequate, while more complex studies might require larger samples.

Data Saturation: This is a key criterion in qualitative research. Data saturation occurs when no new information or themes are emerging from the data. Researchers typically continue sampling until saturation is reached.

Complexity of the Study: The complexity of the research questions and the diversity within the population being studied can influence the sample size. More complex studies or those exploring varied perspectives may need a larger sample.

Homogeneity of the Population: If the population is relatively homogeneous, a smaller sample may be sufficient. Conversely, a more diverse population might require a larger sample to capture different viewpoints.

Resources and Time Constraints: Practical considerations, such as available time, budget, and resources, will also affect the sample size.

Methodology: Different qualitative methods (e.g., interviews, focus groups, case studies) may have different typical sample sizes. For example, in-depth interviews might involve fewer participants than focus groups.

Ultimately, the goal is to gather enough data to provide a comprehensive understanding of the research topic while remaining manageable and practical within the constraints of the study.

Firoj Aktar When you cut and paste an answer from an AI, please provide a citation, just as you would in any other research setting.

Qualitative research is about people lived experiences, so purposively sampling people with such experiences is the key. As a result, a large sample size is not the norm. Also, the intent is not to generalize the findings. Use purposive or convenient samples to select your participants.

in qualitative research since you will be researching and evaluating peoples lived experiences through an interview perhaps, it would be helpful to look at past research with similar or even the same research question and aim to collect a similar sample size! if we are talking about a new research idea you could either find similar studies and recruit your own number of participants evidenced on previous literature or find multiple studies and calculate the mean number of participants they had and that will be your sample size.

Also you can google the various sample methods like purposive sampling, random sampling, snowball sampling, stratified sampling, probability sampling and voluntarily sampling, though it all depends on your research question. Hope this helps!!

One of the issues with qualitative approaches is you need to give at least an estimate of how many subjects you will be interviewing or observing when you are looking for approval of the study. 20 is a reasonable estimate but really using purposive sampling means you find the the type and number of subjects that give you information about the differing components of your topic. You are doing the research because we don't yet have a good understanding of all the component parts of a phenomenon.

Every time you interview a person, you look for what they have told you about the phenomenon. Then you find another subject who can fill you in on more information about a different aspect. I did one study entitled the knowledge base of critical care nurses - what they need to know to do their job. One nurse told me she like knowing the physiology of what is happening to the patient. But then a few of the physiology nurses said other nurses liked the technical part of the job. So I went and interviewed them. Still others liked talking to the patients even when they were unconscious. Still others liked the physical care, more subjects there. So finally I had my headings - the nurses were involved in physiological, physical, technical and psychological care. I interviewed as many subjects as I needed to fully understand each aspect of care that critical care nurses needed to know about to take care of patients as well as how to team up with someone who had different interests and skills. Good luck with your project. I found this type of research to be great fun, too.