Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins Chapter 21 Sampling in Qualitative Research

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins Question Tell whether the following statement is true or false: Qualitative samples tend to be large, random, and intensively studied.

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer False Qualitative samples tend to be small, nonrandom, and intensively studied.

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins Methods of Sampling in Qualitative Research Convenience (volunteer) sampling Snowball sampling Theoretical sampling Purposive sampling

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins Question What is homogeneous sampling? A.Deliberately reducing variation B.Selecting cases that illustrate what is typical C.Selecting the most unusual or extreme cases D.Selecting cases that are intense but not extreme

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer A Homogeneous sampling (deliberately reducing variation), typical case sampling (selecting cases that illustrate what is typical), extreme case sampling (selecting the most unusual or extreme cases), intensity sampling (selecting cases that are intense but not extreme).

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins Purposive Sampling Sampling for representativeness or comparative value Sampling special or unique cases Sampling sequentially

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins Representativeness or Comparative Value Maximum variation sampling Homogeneous sampling Typical case sampling Extreme case sampling Intensity sampling Stratified purposeful sampling Reputational case sampling

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins Purposive Sampling Special Cases Critical case sampling Criterion sampling Revelatory case sampling Sampling politically important cases

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins Question Tell whether the following statement is true or false: Theory based sampling is adding new cases based on changes in research circumstances or in response to new leads that develop in the field.

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer False Theory-based sampling selecting cases on the basis of their representation of important constructs and opportunistic sampling, adding new cases based on changes in research circumstances or in response to new leads that develop in the field.

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins Purposive Sequential Category Theory-based sampling Opportunistic sampling Sampling confirming and disconfirming cases

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins Sample Size in Qualitative Research No explicit, formal criteria Sample size determined by informational needs Decisions to stop sampling guided by data saturation Data quality can affect sample size

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins Sampling in the Three Main Qualitative Traditions Ethnography:  Mingling with many members of the culture  Informal conversations with 25 to 50 informants  Multiple interviews with smaller number of key informants

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins Sampling in the Three Main Qualitative Traditions (cont’d) Phenomenology:  Relies on very small samples (often 10 or fewer)  Participants must have experienced phenomenon of interest

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins Sampling in the Three Main Qualitative Traditions (cont’d) Grounded theory:  Typically involves samples of 20 to 30 people  Selection of participants who can best contribute to emerging theory (usually theoretical sampling)

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins Question Tell whether the following statement is true or false: Analytic generalization occurs when researchers strive to generalize from particulars to a broader conceptualizations and theories.

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer True Analytic generalization occurs when researchers strive to generalize from particulars to a broader conceptualizations and theories.

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins Generalizability Controversial issue Researchers find findings: –Relevant –Meaningful

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins Two Models Analytic generalization: researchers strive to generalize from particulars to a broader conceptualizations and theories. Transferability involves judgments about whether findings from an inquiry can be extrapolated to a different setting or group of people. Transferability has close connections to the proximal similarity model that involves a conceptualization about which contexts are more or less like the one in the study in terms of a gradient of similarity for people, settings, times, and contexts.