Just how many qualitative interviews are required when undertaking research, and how do researchers managing these projects justify such a number?

Professor Mark Saunders

Professor Mark Saunders

“Unsurprisingly”, said co-author and Centre for Work, Organisation and Wellbeing guest, Professor Mark Saunders (Surrey Business School, UK; pictured left), during a 10 March seminar: “There is not a narrow number or norm!”

With WOW member, Associate Professor Keith Townsend, the team analysed 244 articles published between 2003 and 2013 from 10 top-ranking organisation and workplace studies international journals to look at the number of interviews reported in each, their justifications for participant selection, the variety of populations used, and the structure and manner of communication through which the interviews were conducted.

And what did they find?

Reporting on 248 studies that used qualitative interviews, 197 of the articles noted one form of interviewing, 47 used two, and a mere four studies used three. A healthy 85 percent, however, noted the manner by which the interviews were undertaken — overwhelmingly one-on-one (91.1 percent). Underwhelmingly though, nearly one fifth of the 244 did not report a number, and of those that did, only 13.7 percent explicitly justified why such an amount was chosen.

Data saturation, furthermore, – often referred to as the ‘gold standard’ for justification – was used by only 4.2 percent of the studies. Most worrying for the team was the tendency of this group to make such claims without explaining why saturation had been reached.

Associate Professor Keith Townsend

Associate Professor Keith Townsend

As researchers seek to demonstrate why their chosen participant numbers help meet a purpose, Mark and Keith (pictured left)stressed the role that precise reporting has in underpinning an authentic and credible presentation of findings to journal reviewers and their subsequent readership. Building a clear argument of justification using other studies with similar benchmarks is also a pertinent tactic.

Recognising that exceptions exist, Mark concluded that a range of between 15 and 60 participants were typically reported in the articles analysed, although this wide variance may be explained (in part) by the purpose of the research and the homogeneous or heterogeneous nature of the interviewees.

“For some research purposes”, he adds, “one or two interviews could also be sufficient.”

Contact the Centre Manager for a video recording of this session.