Sample Size and Saturation in PhD Studies Using Qualitative Interviews


  • Mark Mason Oxford Brookes University



saturation, sample size, interviews size, personal interviews.


A number of issues can affect sample size in qualitative research; however, the guiding principle should be the concept of saturation. This has been explored in detail by a number of authors but is still hotly debated, and some say little understood. A sample of PhD studies using qualitative approaches, and qualitative interviews as the method of data collection was taken from and contents analysed for their sample sizes. Five hundred and sixty studies were identified that fitted the inclusion criteria. Results showed that the mean sample size was 31; however, the distribution was non-random, with a statistically significant proportion of studies, presenting sample sizes that were multiples of ten. These results are discussed in relation to saturation. They suggest a pre-meditated approach that is not wholly congruent with the principles of qualitative research. URN: urn:nbn:de:0114-fqs100387


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Author Biography

Mark Mason, Oxford Brookes University

Mark MASON has spent more than fifteen years in public sector environments carrying out, commissioning, managing and disseminating research. He began his career working in addictions in psychiatric hospitals. After a successful career in local authorities Mark moved into a policy research analyst post within central government, working initially for the Drugs Prevention Advisory Service in the Home Office. Since then he has worked in a number of social research positions nationally for the last ten years. Over the course of his career Mark has presented and published work on a range of subjects including substance use and community safety. He is currently studying for a PhD at Oxford Brookes University.




How to Cite

Mason, M. (2010). Sample Size and Saturation in PhD Studies Using Qualitative Interviews. Forum Qualitative Sozialforschung Forum: Qualitative Social Research, 11(3).