SAGE Journals

Reinforce chapter themes with free access to two journal articles for each chapter and further online readings. Select chapters will also include suggested weblinks.

Journal Article 5.1: Kristensen, G. K. and Ravn, M. N. (2015) ‘The voices heard and the voices silenced: Recruitment processes in qualitative interview studies’, Qualitative Research 15(6): 727–37.

Discussion Points: Which is the impact of the recruitment operation on the quality of the empirical results? Do the researchers overestimate or underestimate it?

Journal Article 5.2: Malterud, K., Siersma, V. D. and Guassora, A. D. (2015) ‘Sample size in qualitative interview studies: Guided by information power’, Qualitative Health Research 26(3): 1753–60.

Description: Sample sizes must be ascertained in qualitative studies like in quantitative studies but not by the same means. The prevailing concept for sample size in qualitative studies is ‘saturation’. Saturation is closely tied to a specific methodology, and the term is inconsistently applied. We propose the concept ‘information power’ to guide adequate sample size for qualitative studies. Information power indicates that the more information the sample holds, relevant for the actual study, the lower amount of participants is needed. We suggest that the size of a sample with sufficient information power depends on (a) the aim of the study, (b) sample specificity, (c) use of established theory, (d) quality of dialogue, and (e) analysis strategy. We present a model where these elements of information and their relevant dimensions are related to information power. Application of this model in the planning and during data collection of a qualitative study is discussed.