The difference between a case study and single case designs.

this is my first blog in this semester and I apologise if it is a little bit boring 🙂 Hopefully, you will at least find it informative. Have fun reading, xox

In order to see the differences between a case study and a single case study, we need to first understand what these two designs are and what is involved in them. 

Case study is a detailed and intensive study of one person, group, event or community. According to Stake (1995), case study research is concerned with the complexity and particular nature of the case in question. A lot of best-known researchers in psychology and in other areas such as sociology used case studies to investigate different aspects of human nature. For example, most of Freud’s work and theories were developed using this particular design. He conducted very detailed investigations into his patients’ lives in order to understand and help them to overcome their disorders. Most famous case studies of Freud are Little Hans and The Rat Man. In psychology, case studies are often studies of single individual and the information presented in it is mostly biographical. In order to produce such a case study of one person, various techniques may be used. The most common one is an interview, which involves talking to the person of interest as well as to their friends, relatives, employers and others who have a good knowledge of them. other sources of information for a case study are documents, archival records, direct observation and participant observation. So, in a few words case studies provide detailed and rich information, they help researchers to generate new ideas and permit investigation of otherwise impractical/unethical situations.

Single case design or single-subject design is a design that relies on comparison of treatment effects on a single subject or group of single subjects.( Single-subject design are thought to be a direct result of Skinner’s research. This design is sensitive to individual differences. It often involves using large number of participants in a study, however – individuals in the study serve as their own control and therefore the design is called single-subject. Single-subject design has a number of requirements such continuous assessment, baseline assessment and variability in the data. Single-subject designs are quite popular because they are very flexible and highlight individual differences in response to treatment/intervention. Single subject research design is most often used in applied fields of psychology and education.

As you can see, there are a number of obvious differences between a case study and single case design. For one, a case study focuses on one individual whereas single case design studies usually focus on a number of people. For two, case studies look at the history of a person, whereas single-subject design looks at the effects of treatment in one person and then compares it to others. However, the most important thing to be mentioned is that single-subject designs improve on case studies and therefore they are, in my opinion, a more extensive source of knowledge.

References: Mcleod, S. A. (2008). Simply Psychology; . Retrieved 3 February 2012, from

Social research methods by Alan Bryman – 2nd edition.



  1. psud60 said,

    February 10, 2012 at 10:16 pm

    In your blog you have mentioned that single – subject design looks at the effects of treatment in open person and then comparing it to others yet you have not mentioned the use of ABAB design which is a reversal design which is a single- subject experimental design consisting of four phase: the baseline, a treatment phase, a return to baseline phase and the second treatment phase is quite a thorough design but it does effectively demonstrate that the treatment causes change in the participant behaviour. Which I feel would greater extend the source of knowledge which you speak of in your blog.

  2. kmusial said,

    March 13, 2012 at 12:19 pm

    Single case studies can be very important in research. However they may not be suitable for any research question. In the research of Thierry et al.2007 they found that the N170 stimulus is not face selective. For a question like this have ERP results of only one participant, in form of a graph of an average activity of the brain would tell you nothing. However there have been many cases in the past where patients with extreme lesions have been identified. As an example it could be worth looking at Broca’s patient Leborgne, or Werkicke’s patient Tan. These single case studies are especially important as patients with such lesions are extremely rare. Therefore there would be no other way of testing them than a single case study.

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