Hi Castellani

Yes of course you may be allowed to that. However, for the purpose of triangulation, I'd advice that you add any other data collection instruments such as observations/questionnaire/documentary reviews

Hi Carmenn The characteristic that define the case study method is the combination of multiple sources of data. May be you can look for other sources of data for your study on order to define it as "multiple case study". May be you can interview another people that also are involve in the phenomenon and you could triangulate the information.

Laila Rahman thank you for your extensive reply. Unfortunately, it is not possible to include documentation or physical artifacts to my data collection.

I saw in another post that semi-structured interviews can be considered as a type of survey research approach in qualitative studies.

I was wondering if you know any reference that mentions that. So far, I only found books/articles that consider survey a quantitative research approach. Thanks again!

In a quantitative methodology we denominate semi-structured interviews when you have open and closed questions. In qualitative study all the questions inside an interview are "open question" and as interviewer you have to question again from the answer to deepen it, to know more details and specificity.

The denomination of semi structured interview as well in qualitative studies is referreing to the fact that you have an interview format with few defined questions, but you dont have alternatives or optional answers. For this reason the semistructured interview in the context of qualitative study is in essence different to the semistructured at survey research. I hope I help you.

I think the most important aspect of Yin's approach is to build a "portfolio" of data that makes detailed comparisons across a set of cases. An important part of that strategy is to fill in a systematic data set that addresses all the major issues you uncover across the full set of cases -- in other words, an iterative strategy where things that you learn at one site generate issues to be addressed at the other sites.

This would be difficult to do if you are conducting one interview per site and using the same set of questions in each interview.

I suggest to use multiple methods eg. questionnaires and interviews with the same characteristics as a rule of thump to obtain enough and dependable data from different angles of people's experiences and observations for the study's authenticity.

@I suggest you use multiple methods such as;focused group discussions,observations and structured questionnaires to obtain adequate reliable data.

it is possible to have only in-depth semi-structured interviews, it is recommended to have another method for collecting data to triangulate your data.

the article attached might help

Mixed method will give you better outcome in such a topic and you can make it with a small sample too.