Dear Um, He did not identified the exact amount of samples in his book. But I should remember two different sampling concepts in case study research. First one is about choosing the number of cases for a multiple case study research, in which we study a case in multiple locations, or we study multiple cases (subjects) in a location. In these situations the number of cases could be identified by research scope. For example, when we want to investigate sustainability issues in Pharmaceutical industry we can choose 10 companies in that and researching sustainability there. The number 10 is not challenging here, because we do not have any claim about generalization of results, we just want to study this subject by largely details. But it may be a single case study in a company or supply chain or an office. Here, for gathering data we should obey the principle of "triangulation". it means that, In a case study we can use multiple research methods, multiple data gathering methods, multiple sources of data. It is clear that you can use survey research too. But when you are employing that, you should follow the sampling strategies whether statistical or not.

Good luck. I will be available for other questions, too. :)

The question is really irrelevant in the discussion of qualitative case study. The idea here is description and explanation of the case instead of trying to get a random sample of cases. In this case we recognize that it doesn't necessarily generalize to any other case but it at least explains this one.

When we have multiple cases, the idea is to get contrasting situations. E.g. one case where the phenomenon we are studying occurred and one where it didn't and then try to explain how the differences between the cases explain why it occurred in one and not in the other.

So you will want to get as many cases as have different conditions related to the phenomenon under study. You don't need ones that duplicate any of the others.

There is no singly acceptable number of participants to be interviewed in a qualitative research enterprise: it all depends on the one you think can settle the demand of your research. For instance, Cresswell (2008) suggested for between 5 to 25 ; Adler and Adler; Baker & Edwards (n.d) all chose from 12 to 60 and 30 being the mean ; Glaser and Strauss (1967) sees saturation to be the point of diminishing return i.e when the data has started repeating itself. But alot of scholars pegs 15 to be the least. For Yin, I suggest you get his book titled as below:

Yin, R. (1994). Case Study Research: Design and Methods. London: Sage.

You will be more refreshed!

I have only four cases for my research . Can I still refer to it as a case study method?. It seems from my data i have reached saturation already as my results converged.

Can I still refer to it as a ' case study method' or are there are any alternatives nomenclature , i can use.

Thank you for your help.

Eun K Um Yin (2009) noted that due to the nature of the case study approach, “the typical criteria regarding sample size are irrelevant.” Yin (2009) also notes that the researcher should rather focus on getting information on the various aspects of the case. Creswell (2013) notes that this is, in reality, getting different perspectives on the phenomenon under study. Creswell (2013) calls this sampling process, ‘purposeful maximal variation’.

I suggest that you look at your areas under probe and establish and initial number of participants. Be open to the fact that this number can snowball or shrink.

Scholarship has one important debt: improving our appreciation of case study. Always start by visualizing a space. Ask, what is in this space? What is happening? When we appreciate dynamical systems, the essence of case study becomes clear. Case study is the answer to the intractability of dynamical systems. Cf. Article Parsing Competitive Dialogue in Public-Private Partnerships:...

It depends whether you are doing a single case study or a multiple case study. Also whether they are holistic or embedded. The more the cases the more robust is your study.

@ S Sidki

You have provided relevant information in the context.

Hi Guys,

I am working on my Thesis. I want to do a case study with 3 interviews. The case is a start up. the topic is about founding a start up. I want to do an interview with 3 different entrepreneurs. Which is the right design regarding Yin? Holistic or embedded single case study?

Many thanks for your help!! :-)

Yours is a multiple case study brother. And, I hope you have a very good justification for selecting the three entrepreneurs because case study requires in-depth investigation which I believe your informants cannot provide. Besides, qualitative research mostly allow data to determine the number of informants based on the opinions of Glaser and Strauss (1965) on data saturation. Though, Creswell, Adler and Adler and some scholars pegged numbers I.e. from five and above. Please, Google more and see. Best wishes