How Many Interviews Are Enough?

  title={How Many Interviews Are Enough?},
  author={Greg Guest and Arwen E. Bunce and Laura Johnson},
  journal={Field Methods},
  pages={59 - 82}
Guidelines for determining nonprobabilistic sample sizes are virtually nonexistent. [...] Key Result Based on the data set, they found that saturation occurred within the first twelve interviews, although basic elements for metathemes were present as early as six...Expand
Theoretical sampling.
The authors' experience involves a study conducted in a large hospital in Northern Italy on the validation and application of standards on the involvement of children and their families in the healthcare process, which induced us to develop within the scope of this project with a quantitative design, a secondary study on the psychosocial processes of therapeutic self-care. Expand
What is an adequate sample size? Operationalising data saturation for theory-based interview studies
This work proposes principles for deciding saturation in theory-based interview studies, and demonstrates these principles in two studies, based on the theory of planned behaviour, designed to identify three belief categories (Behavioural, Normative and Control). Expand
How Many Focus Groups Are Enough? Building an Evidence Base for Nonprobability Sample Sizes
Few empirical studies exist to guide researchers in determining the number of focus groups necessary for a research study. The analyses described here provide foundational evidence to helpExpand
Is Sampling a Misnomer in Qualitative Research?
This paper explores the meaning of sample and its relevance in different types of qualitative research and distinguishes them from the way it is used in a statistical sense. The idea of sampling mayExpand
Sample Size in Qualitative Interview Studies
It is suggested 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. Expand
Open-ended interview questions and saturation
The concept of saturation in salience is advanced and probing to increase the amount of information collected per respondent to increase sample efficiency is focused on. Expand
How Many Interviews Are Enough to Identify Metathemes in Multisited and Cross-cultural Research? Another Perspective on Guest, Bunce, and Johnson’s (2006) Landmark Study
There is much debate over the number of interviews needed to reach data saturation for themes and metathemes in qualitative research. The primary purpose of this study is to determine the number ofExpand
Analytic Strategies and Sample Size
  • J. Morse
  • Psychology, Medicine
  • Qualitative health research
  • 2015
But there is more: It also depends on the investigator— how theoretically smart, how well these data are theoretically sampled and verified, how well funded, how much time allotted, and how patientExpand
A simple method to assess and report thematic saturation in qualitative research
This work describes and validate a simple-to-apply method for assessing and reporting on saturation in the context of inductive thematic analyses and proposes a more flexible approach to reporting saturation. Expand
An Examination of the Sufficiency of Small Qualitative Samples
Qualitative researchers often confront dilemmas regarding determining what constitutes a robust sample size. The challenge is to find a sample that will produce thorough and meaningful findings whileExpand


Sample size in qualitative research.
Determining adequate sample size in qualitative research is ultimately a matter of judgment and experience in evaluating the quality of the information collected against the uses to which it will be put, the particular research method and purposeful sampling strategy employed, and the research product intended. Expand
Techniques to Identify Themes in Qualitative Data
Theme identification is one of the most fundamental tasks in qualitative research. It also one of the most mysterious. Explicit descriptions of theme discovery are rarely described in articles andExpand
The Discovery of Grounded Theory: Strategies for Qualitative Research
Most writing on sociological method has been concerned with how accurate facts can be obtained and how theory can thereby be more rigorously tested. In The Discovery of Grounded Theory, Barney GlaserExpand
Culture as Consensus: A Theory of Culture and Informant Accuracy
This paper presents and tests a formal mathematical model for the analysis of informant responses to systematic interview questions. We assume a situation in which the ethnographer does not know howExpand
Techniques to Identify Themes
Theme identification is one of the most fundamental tasks in qualitative research. It also is one of the most mysterious. Explicit descriptions of theme discovery are rarely found in articles andExpand
Evaluating qualitative research.
The outline that follows was based on a review of how qualitative research on human experience was being conducted and reported and includes lists of evaluative criteria for assessing (a) good practice in conducting the research and (b) validity of interpretations. Expand
Intercoder Agreement in Analysis of Responses to Open-Ended Interview Questions: Examples from Tuberculosis Research
Social scientists commonly conduct surveys to learn about beliefs, attitudes, reported behaviors, or experiences prevalent in a population. These interviews often involve the use of structuredExpand
Codebook Development for Team-Based Qualitative Analysis
Given the context of the interdisciplinary nature of research at the Centers for Disease Control and Prevention (CDC), this work has sought to develop explicit guidelines for all aspects of qualitative data analysis, including codebook development. Expand
Understanding and Evaluating Qualitative Research∗
This paper aims to provide beginning researchers, and those unfamiliar with qualitative research, with an orientation to the principles that inform the evaluation of the design, conduct, findings and interpretation of qualitative research. Expand
Respondent perspectives on self-report measures of condom use.
A study using semistructured interviews was conducted to elicit the perspectives of women who had participated in a microbicide clinical trial in which self-reports of condom use were included, finding that a number were able to articulate strategies for remembering their condom use. Expand