I am not a great fan of phenomenology, but from the little I know, I think that  your cut-toff sample cannot and should not be informed by the principle of  randomization. Rather, instead it would be informed by the selection or inclusion of the  largest sample variables on the assumption that the largest categories can usually predict or include the smaller ones. I  assume in this case  that you refer to the interpretative form of phenomenology.

A phenomenological approach would necessitate finding or trying to identify a homogeneous sample. The basic logic being that it cannot be helpful to consider random or representative sampling. In contrast, phenomenology would rather engage with purposive sampling by mapping out boundaries for relevant groups for whom the research question will be significant. By mapping out these boundaries, it seems to me that your cut-off point/sample cut-off has already been pre-determined. The trick is to try and accommodate as many representatives of that defined boundary as you can.  Determining the boundary will, therefore, be dictated by the nature of the study and the questions you set out to answer.  As noted by Smith and Osborne (2007), ' in some cases, the topic under investigation may itself be rare and define the boundaries of the relevant sample. In other cases where a less specific issue is under investigation, the sample may be drawn from a population with similar demographic/socio-economic status profiles'. See the link below to the referred article, which I think can be helpful.

http://www.sagepub.com/sites/default/files/upm-binaries/17418_04_Smith_2e_Ch_04.pdf

Your cut-off  point is when you reach saturation.  After your initial interviews, you should continue to interview 3 additional participants until no new themes, categories, or information emerges.  This will be your cut-off point.   

I agree with Shirley that the cut-off point should be when you have sufficient data for your qualitative analysis since data collection and analysis are concurrent. However you still have to make an educated guess at the recruitment stage depending on the population and success rate of sample sizes in similar studies in the past. Not all recruited participants may end up participating in the study. For example, I had planned to interview ten Directors to gain some insights into a systemic phenomenon but I succeeded interviewing only five of them.

I agree that the cut-off point is when you get saturation - that is when new cases do not give you any new information. However, this may be hard to assume, because even if you think you get saturation at feks 15 - participant 17 and 18 may give you new information. I do not agree with the first commenter, that the sample in phenomenology should be as homogeneously as possible, because the opposite is the case: yous should try to get  as vary sample as you can to inform you about the different aspects under study. Here; I advise you to go to the methodology literature on qualitative research and in special phenomenology. I will also recommend the paper: Francis, J. J., et al. (2010). "What is an adequate sample size? Operationalising data saturation for theory-based interview studies." Psychol Health 25(10): 1229-1245. (attached). This will perhaps help you.

Phenomenological understanding is always underway, therefore one cannot speak of adequate sample size or "saturation," partly because of the hermeneutic recognition that interpretation can never be complete.and is always underway. Any set of lived descriptions can be interpreted in a wide range of ways, and typically my interpretation will not be yours.

Also, phenomenologically, one cannot speak of sample size. Rather, the aim is to gather descriptions as one can. Depending on the phenomenon being studied, this can be relatively easy or very, very difficult. What is important is the quality of the descriptions--i.e., some respondents are more perceptive, they are more articulate, they are more interested in the phenomenon. Vivid, perceptive accounts are the best descriptions to find, draw from, and trust the most.

Two useful introductions to phenomenological research are Linda Finlay's PHENOMENOLOGY FOR THERAPISTS and Max van Manen's PHENOMENOLOGY OF PRACTICE (2015). Also see my review chapter on qualitative methods at my home page at academia.edu.

David Seamon

I think there is need for caution however. Social Science is a broad field with several disciplines. Phenomenological studies vary from one discipline to another. The idea behind sampling in scientific investigation is generalization or typical description of the phenomenon to the given population. Ignoring the need for sample could reduce scientific research to journalistic fact-finding or opinion. Another researcher should be able to replicate a scientific research in similar settings of the given population.

I  have to agree with David, understanding (interpreting) phenomenon involves uncovering multiple layers of meaning.  A hermeneutic phenomenological study usually involves asking people to tell their story of lived through experiences of the focus of the study.  Gathering stories is time consuming as is the process of transcribing, iterative reading, and analysis.  Though the time spent is extremely rewarding, as the researcher uncovers deeper meaning than anticipated.  Therefore, I would suggest being cautious on the sample size, remembering quality over quantity is central to bringing something new to the existing literature. 

Denise,

Your comments are well taken and it is exactly as you say--the possibility of locating "multiple layers of meaning," often those that the researcher had no idea about when he/she began his/her phenomenological investigation. Though some phenomenologists do, I never speak of "sample" or "sample size" or "subjects" or "data." These are all quantitative/positivist terms that have little lived grounding phenomenologically. More accurate terms are "respondents," "co-researchers," "participants," "evidence," and "descriptions." Terminology plays a major role in understanding and conducting method, so one should use a language in sync with the basic methodological principle of phenomenological research--that the phenomenon is allowed to reveal itself in its own time in the manner and language whereby it can best be and express itself. Husserl's "to the things themselves."

Hi Richard, you look at what others have done [other Walden dissertations, for example] in the scholarly research.  Then, you speak with your doctoral chair about it.  He/she can guide you in choosing an appropriate number.  Jan Vinita White, PhD, Walden University, Gerontologist. 

I agree with David S. Phenomenologically speaking, there is no end point for ephemerally based research.

Empiricism, which is the basic platform for observational studies cannot reach "saturation" in a quantitative sense.

My answer ultimately would be more rudimentary: time and money are the only quantifiable limitations and their impact has to be factored into the results.

Hello,

Here is an interesting article about the saturation point in qualitative research.

Isabelle

P.S: you could read this one too: 

Guest, G., Bunce, A., & Johnson, L. (2006). How many interviews are enough? An experiment with data saturation and variability. Field Methods, 18, 59-82. 

If you are seeking to achieve saturation in your research, this can only be determined as the study progresses and occurs when you find additional participants are no longer providing fresh additional data. Saturation is seldom achieved because who has enough resources to keep adding participants in this way? The cut off size of a sample in qualitative research is more often determined in advance by resource limitations and other logistic realities. Master's level research, for example, will have less participants than PHD level research. There are often timelines that accompany research that cannot be denied and may as well be acknowledged. You can make up some rationalization to make it look like there are methodological reasons for such limitation, but would this be honest?

As I suggested above, "saturation" is not part of phenomenological method but a term used in grounded theory. The aim phenomenologically is an accurate, comprehensive description and interpretation of the particular phenomenon. How this is to be had is almost entirely dependent on the nature and constitution of the particular phenomenon. Different phenomenon will involve different methodological approaches.

The best discussion of this matter is van Manen's PHENOMENOLOGY OF PRACTICE (2014).

I did my master's research using phenomenology as a methodology but interpretive grounded theory for data analysis. Phenomenology provides an excellent overarching methodology if one wants to explore experience as a way of generating data and insight, but phenomenology involves no inherent methods. This is where interpretive grounded theory comes in (I say interpretive grounded theory ala Charmaz because original grounded theory does not seem compatible with interpretive methods like phenomenology). Anyway, this is where saturation can become an issue to consider. It is important when using the term "methodological" in research to distinguish between the framework setting methodology and the techniques or actual methods used. These must be consistent, but are not the same thing. Thank you for the reference to Phenomenology of Practice. 

I agree with David Seamon. The Grounded Theory of "Saturation" has crept into qualitative research from the old days when there were really only two qualitative approaches - ethnographic and (from the late 1970s) Grounded Theory. In Phenomenological research the most often cited "ideal sample size" is seven - 7. The larger the sample size. the more lost are the voices which you are trying to represent in your study. Ask yourself this question: "How many can I include before I am unable to present honest accounts of their experiences?" The larger the number, the more reductionist your study becomes.

This article is also useful in determining adequate sampling size for a qualitative research: Malterud, K., Siersma, V. D., & Guassora, A. D. (2016). Sample Size in Qualitative Interview Studies. Qualitative Health Research, 26(13), 1753–1760. doi:10.1177/1049732315617444

Further to the sample size as recommended by Sandelowski (1995); Mason (2010), please refer to the propositions by Wertz (2005, p. 171) that “ 'the question of ‘how many participants?’ can be answered properly by considering…….in-depth knowledge of individual’s experience…..it is not always possible to determine the required number of particular participants…..the researcher may deliberately continue recruiting different additional participants until saturation."

• Mason, M. (2010) Sample Size and Saturation in PhD Studies Using Qualitative Interviews, Forum, Qualitative Social Research, 11, 3, pp. 1-20.
• Sandelowski, M. (1995) Sample size in Qualitative Research, Research in Nursing and Health, 18, 2, pp. 179-183.
• Wertz, F. J. (2005) Phenomenological Research Methods for Counseling Psychology, Journal of Counseling Psychology, 52, 2, pp. 167-177.

Thanks. Your answers were really informative. Could you tell me pls whether phenomenological method has any study design notation?

Very helpful responses. Thanks everybody. I have used saturation for all qualitative studies,

This conversation is very helpful. Thank you.

There is no specific number. It includes the number of participants in the lit review from non-funded studies, what your committee/school/university will accept, and how many are required to answer your reseach question.

Some may find useful to refer to a series of four articles. Series: Practical guidance to qualitative research. Part 3: Sampling, data

collection and analysis

Albine Mosera,b and Irene Korstjensc

EUROPEAN JOURNAL OF GENERAL PRACTICE, 2018

VOL. 24, NO. 1, 9–18

https://doi.org/10.1080/13814788.2017.1375091

Theoretical satuartion. Refer to Cathy Charmaz.

8-15. No less, no more.