Case Study Designs
Research Objective
Study relationships
among variables for
existing groups
Show direct cause &
effect
Explain outcomes
after the fact
Type of Design
Cross-Sectional
Longitudinal
True Experiment
Quasi-Experiment
Explanatory Case Study
Exploratory Case Study
Purpose
• The purpose of the case study is to explore,
understand and explain the processes and
events that have led or contributed to one or
more states or conditions of interest.
Distinctive Features
• Unlike all experiments and all prospective crosssectional or longitudinal designs, in the case
study we work “backward” from a known state or
condition.
• Cases are selected because they exhibit the one
or more states or conditions of interest.
• Cases are selected based on the observable
outcome of processes and events over time.
• The state or condition usually refers to the
current situation, but can refer to a condition or
situation that existed at some point in the past.
When to Use Case Studies
• We use exploratory case studies when we
observe a state or condition that is hard to
understand, unanticipated, surprising –
something that the current body of
knowledge and theory will not explain
adequately
• We use explanatory case studies when we
want to build or test theoretical explanations
for a condition or state of interest
Did you use one or more theoretical frameworks to develop the research
question(s)?
Yes
No
Not a case study
Did you develop propositions about the relationships between theoretical
constructs or concepts based on those theoretical frameworks?
Yes
No
Did you state the purpose of the study and the criteria by which
the quality (success) of the study will be evaluated?
Yes
Exploratory case study
No
Not a case study
Did you select multiple cases (replications) for study?
Yes
No
Multiple case
explanatory study
Single case explanatory study
Did you use
embedded units?
Yes
Embedded
No
Holistic
Common MISperceptions
• There are many common misperceptions
about case studies. By the time you study Yin,
you should be able to explain why each of the
following statements is a MISperception.
Common MISperceptions
• The case study is the same thing as the “one shot
post-test only quasi-experiment.”
• The case study is the same thing as an
ethnography, life history analysis, or grounded
theory.
• Case studies do not depend on identifying one or
more theories that serve as the basis for
developing the research question.
• Case studies do not require an careful statement
of the systematized definitions of constructs of
interest.
Common MISperceptions
• There is no need to state a proposition (or
hypothesis) in the case study design.
• There is no need to define a theoretical or
accessible population in the case study design.
• There are no guidelines (rules if you will) for
selecting the cases.
• Results of case studies cannot be generalized.
• The case study does not require any
consideration of threats to internal validity,
external validity and explanatory power.
Common MISperceptions
• Case studies do not need a sample size of
more than one.
• Case studies can only be used to build, not
test theory.
• Case studies are just like cross-sectional or
longitudinal designs, except for how the
sample is selected.
• Case studies share nothing in common with
experiments.
The WORST Misperceptions
• You do not need much advance thinking or
preparation to conduct a case study – you can
start collecting data very quickly.
• A case study is a quick and easy way to
complete a study.
• You do not have to concern yourself much
with analysis in case studies because they are
simply descriptions.
Common Uses Outside the Social Sciences
• Another common misperception is that case
studies are only used in the social sciences.
Quite the contrary, many disciplines make
widespread use of this design group. These
include, for example
– Geology and other earth sciences
– Paleontology
– Cosmology (how the universe formed and
developed)
– Forensic sciences (CSI, autopsy, and all that)
– Evolutionary biology