1. Copyright © 2011, 2005, 1998, 1993 by Mosby, Inc., an affiliate of Elsevier Inc. Chapter 23: Case Study Designs

2. 2 Copyright © 2011, 2005, 1998, 1993 by Mosby, Inc., an affiliate of Elsevier Inc. Definition (Yin, 2008)  Part One: “An empirical inquiry that…investigates a contemporary phenomenon within its real life context; especially when the boundaries between phenomenon and context are not clearly evident”  Part Two: “Copes with the technically distinctive situation in which there will be many more variables of interest than data points, and as one result, relies on multiple sources of evidence, with data needing to converge in a triangulating fashion, and as another result, benefits from the prior development of theoretical propositions to guide data collection and analysis”

3. Copyright © 2011, 2005, 1998, 1993 by Mosby, Inc., an affiliate of Elsevier Inc. What is a Case Study? A Case study is a detailed, in-depth description of a single unit, subject or event. Case study designs may involve multiple persons or units. This is an approach that is used to investigate a “single phenomenon” in context.

4. Copyright © 2011, 2005, 1998, 1993 by Mosby, Inc., an affiliate of Elsevier Inc. What is a Case Study? Characteristics of Case Study Designs Flexibility Used by either Experimental-type or Naturalistic tradition Multiple purposes Multiple data collection methods A critical element is its reliance on multiple methods of data collection (triangulation or crystallization)

5. 5 Copyright © 2011, 2005, 1998, 1993 by Mosby, Inc., an affiliate of Elsevier Inc.  Crystallization: collecting information using different strategies to examine a phenomenon is a basic strategy in case study designs  Can also use mixed methods

6. Copyright © 2011, 2005, 1998, 1993 by Mosby, Inc., an affiliate of Elsevier Inc. When is a Case Study Useful? When it is not possible or desirable to randomize When it is not possible or desirable to study a particular population as a group with similar characteristics When it is desirable to determine intervention outcomes When it is desirable to obtain pilot information in a cost-efficient way

7. Copyright © 2011, 2005, 1998, 1993 by Mosby, Inc., an affiliate of Elsevier Inc. Yin Classified Case Studies into 4 Categories Created through Combining 2 dimensions: The Structure of The Unit of Analysis Holistic or Imbedded The number of cases Single or Multiple

8. 8 Copyright © 2011, 2005, 1998, 1993 by Mosby, Inc., an affiliate of Elsevier Inc. Structure  Holistic: unit of analysis is viewed as a single global phenomenon  Embedded: unit of analysis viewed as multiple subparts or as subparts placed within larger contexts

9. 9 Copyright © 2011, 2005, 1998, 1993 by Mosby, Inc., an affiliate of Elsevier Inc. How Many?  Single-case design: only one study of a single unit of analysis is conducted  The holistic single-case study is conducted only once on one case. The holistic multiple-case study examines several global units of analysis more than once.  Multiple-case design: more than one study of single units of analysis is conducted  An embedded single-case study focuses on multiple parts of a single case using only one case. An embedded multiple-case study examines more than one case in which each case contains many subparts.

10. 10 Copyright © 2011, 2005, 1998, 1993 by Mosby, Inc., an affiliate of Elsevier Inc. Experimental-Type Design Sequences  Notation  A = observation, B = intervention or independent variable  Variations AB AB ABA ABA ABAB ABAB  Time series

11. 11 Copyright © 2011, 2005, 1998, 1993 by Mosby, Inc., an affiliate of Elsevier Inc. Naturalistic and Mixed Method  Varied sequence and structure