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7.12 Summary 183

be hard to convince some critical readers that case study research is worthwhile.
“This study only includes one participant,” they might say, “so how can we apply it
to others?”
Case studies that make broad claims of generality are particularly likely to in-
furiate these critics, who may feel that any generalization from case studies is inap-
propriate. When conducting and describing case study research, always take care to
remember the limits of this approach, and try to avoid making claims that cannot be
sustained by a small number of cases.
Although concerns about validity and reliability are certainly appropriate, critics
of case studies risk the loss of a valuable research tool. In digging deep into concrete
situations, they can help researchers identify design particulars that are likely to go
unnoticed by research in usability labs. In focusing on specific situations, they provide
concrete illustrations of needs, motivations, and successes or failures. As explanatory
tools, they take requirements from the abstract to the specific. Particularly when pre-
sented alongside complementary user studies that provide broader-based data, case
studies can paint rich pictures that deepen our understanding of complex phenomena.
Case studies succeed when they build upon the fundamental human activity of
learning through story-telling. If your case study can use the details of a specific
situation to tell the story behind some HCI research question, it will succeed in its
ultimate goal of increasing understanding and communicating that understanding to
a broader audience.

DISCUSSION QUESTIONS

1. Case studies can be useful tools for exploring user requirements for software
tools, but they present challenges: given a small number of cases, your results
may not be generally applicable. Some user requirements from a case study
might be easy to implement with minimal impact on a design—these might be
included even if they are not of broad interest. Other requirements might require
fundamental changes to system design. How can you be confident that you
have gained a thorough, general understanding that is suitable for designing an
application of broader interest? If additional cases are not available, how might
you use other HCI research techniques to bolster your confidence in the results
of your case study?
2. Case studies involve working closely with individuals who may have a
substantial interest in the results of your work. This might lead some participants
to put “spin” on their interactions with you, framing their activities and
responses to questions to increase the likelihood of achieving their desired
outcomes. How might you design your study and choose your data sources to
account for this concern?
3. Although the case study of Sara's use of technology is a good example of case-
study research, our discussion of it represents a different type of case study: