Supervisors thinks I need 40 to 50 though! Don't know where I'm going to get that many from! Seems like overkill to me ...

Thank you for your thoughts. Yes a post doc I spoke to also mentioned 20 as a min. I think the quality issue you raise is an important one too :)

Thanks RLD - I think that is the same one that Clementine posted, right? It's a good one though, so perhaps worthy of a second posting :) cheers!

Thank you for all your responses - the feedback has been insightful.

thanks for the reply RLD. Yes, I was hinting that the sample size is small when one considers the seniority of the interviewees. Both my supervisors are qual. by trade so I've had little "statistical input" - from your perspective what percentage of a given sample ought to be interviewed to ensure "validity" etc.? I'm struggling to get more than around 20-25 due to the access isssue you mentioned - will this be problematic in your view? Also, you say that you used three separate sample populations - would you suggest the number of interviewees should be (roughly) equally distributed among these?

Would 20 be enough?

Hi all. Doubtless this has been asked before but I wanted some thoughts on my particular situation. I'm conducting research into stroke care. The bulk of my data comes in the form of semi-structured interviews with clinicians (but also from a few nurses/allied health professionals). The clinicians are all consultant level (some combine their clinical activities with academic ones, so are Profs. as well as medical doctors) i.e. leaders in their field.

The telephone interviews last anywhere from 25-45 minutes. Given the seniority of the interviewees, what number would be sufficient for a PhD thesis? I will be transcribing the interviews and then manually coding them/looking for themes etc.

Thank you!