Statistics in grounded theory research

People asked questions like "how many interviews should I have?", "how do I know it's saturated?" There are some tips I got that may help you to check your research. They are not rigid rules, but for your references only.

• The literature review demonstrated that saturation normally occurs between 10 and 30interviews. Although saturation might occur after the tenth interview, it is good practiceto test the level of saturation by conducting a few more interviews. ... Thus, it would be wise to anticipate 30 interviews in order to facilitate pattern, category, and dimension growth and saturation. It is only through the quality of the data that meaningful and valid results are developed, so it is essential that the researcher ensure that saturation has occurred (Thomson, 2011, p.50).
• Saturation is achieved when one has conducted between 25 and 30 interviews (Suddaby, 2006).
• 10-15 minutes to 40 minutes interview will reach theoretical saturation (Wuest, 2007).
• Do not put red and green slices next to each other, because 5% of population cannot distinguish red from green. (Fink, 2003, p.9).
• A 40 minutes interview may take you 2 days to transcribe. One hour interview will be transcribed into about 15 pages text.

Bibliography:

• Coyne,  I.T. (1997). "Sampling in qualitative research. Purposeful and theoretical sampling; merging or clear boundaries?". Journal of Advanced Nursing. 26 (3), 623-630.
• Fink, A. (2003). The survey kit, vol. 10: How to report on surveys, 2nd ed. London: Sage.
• Morse, J. M. (1994). Designing funded qualitative research. In: Denzin, N.K. & Lincoln, Y.S. (eds.), Handbook of qualitative research, 2nd ed., pp.220-35. Thousand Oaks, CA: Sage.
• Mason, J. M. (2010). "Sample Size and Saturation in PhD Studies Using Qualitative Interviews". Forum Qualitative Sozialforschung / Forum: Qualitative Social Research, 11 (3), Art. 8.
• Suddaby, R. (2006). "From the editors: What Grounded Theory is Not". Academy of Management Journal, 49 (4), 633–642.
• Thomson, S. B. (2011). "Sample Size and Grounded Theory". JOAAG, 5 (1). 45-52.
• Wuest, J. (2007). "Grounded Theory: the method". In: Munhall, P.L. (ed.), Nursing research: a qualitative perspective, pp. 239-272. Sudbury, Mass. ; London: Jones and Bartlett.
• A discussion about "Grounded theory sample size" on the Methodspace - home of the Research Methods community.