The consistent answer across all those discussions is that there is no way to predict then sample size for a qualitative study. Instead, it depends on saturation, which you need to experience during the data collection itself.

Versions of this questions have been asked many times here, so I suggest you do a search to find those previous discussions.

@David L Morgan, I know about that and have also read your comments on them. But, I still need an answer from you on this because I have less than four months to complete my Disertation research.

The approximate population of my area of study - Yenagoa, is about 1.5 million. I want to know if my ideal sample size/number of respondents, especially the IDI target, is okay to cover the social problem at hand - gangsterism. Also is it compulsory or necessary to carry out an FGD in this study considering the less time I have? If Yes, then how MANY of the Focus Group Discussions will be enough?

The consistent answer across all those discussions is that there is no way to predict then sample size for a qualitative study. Instead, it depends on saturation, which you need to experience during the data collection itself.

In other words, I have to state the sample size/number of respondents only after I have come back from the field?

I agree with Mr Morgan. Saturation will always be the key.

In the past, dealing with an obligation to plan in advance the number of interviews (for budgetary concerns) , I found usefull this article from Gest an al. on that topic. To be used with caution, although..

Guest, G., et al. (2006). "How Many Interviews Are Enough?: An Experiment with Data Saturation and Variability." Field Methods 18(1): 59-82.

Without population and objectives, we can't say but 30 is ok for perception

Obebinaru - Sample size in qualitative depends upon several factors; 1) Qualitative research typically require a smaller sample size than quantitative research, 2) The sample size in any qualitative study mainly depends on the concept of saturation and the goal of qualitative researchers should be the attainment of saturation. Saturation occurs when adding more participants to the study does not result in additional perspectives or information, 3) The number of data collection methods (e.g. observations, open-ended survey, focus group interviews etc) does play a role in sample size. The method of triangulation helps to reach the researcher to a saturation much earlier if you rely on interviews and the number could be as small as 10-15 interviews only.

All your analyses have been great. I will go with a target-population of 30 respondents for a start, and will stop if I attain saturation.

I thank you all once more. I have gone and returned from the field, and my findings on the issue of Gangsterism in Yenagoa, Nigeria, were amazing. I was able to interview over three different real gang-affilliated members, the Police, community leaders, residents and academics, and 2 FGDs. I got to saturation after about six Qualitative interview despite planning earlier to interview at least 20 people.

Over seven of the interviews/FGDs were taped on my phone after the respondents' permission, except where I was making a Participant Observation and needed not to take their permission in order to dig deeper into their gang lifestyles and secret codes.

no hard and fast rules regarding sample size feasible no. and how indepth data collection happens is important and analysis based on interviews group discussions and actual opinion and words of subject and how collectively these things are summarised in important