Case Studies (DP IB Psychology: SL): Revision Note

Case studies

• Case studies are detailed and in-depth investigations of a small group or an individual

• Case studies allow researchers to examine individuals who have undergone a unique or rare experience or who are unusual in some way

  • E.g., someone who had a hemispherectomy to treat their epilepsy

  • someone who spent their childhood living in a cult

  • someone who presents with dissociative identity disorder

• Qualitative data may be collected using interviews, observations, open-ended questions on a questionnaire

  • This means that case studies are a good means of reporting subjective, individual experience that is highly personal and relates only to the participant(s)

• Case studies can also generate quantitative data

  • E.g., memory tests, IQ tests, closed questions on a questionnaire

• If a case study employs more than one method (e.g., interviews plus observations plus memory tests), it is referred to as triangulation

  • Triangulation of data involves generating more than one set or type of data in the same study

  • Triangulation of research involves using more than one researcher to collect, analyse (or both) in the same study

• Most case studies tend to be longitudinal

  • A participant's experience/progress is tracked and measured over time

  • The case study may take weeks, months or even years to complete

• The case of HM is an example of a case study of an individual with brain damage

  • Qualitative data was obtained via interviews and observations of HM both at home and in the hospital

  • Quantitative data was obtained via memory tests, IQ tests and MRI scanning of his brain

  • By studying HM so closely for years, the researchers were able to conclude that the hippocampus plays an essential role in the formation of new memories (short-term memory specifically)

Evaluation of case studies

Strengths

• Case studies provide rich, in-depth data which is high in explanatory power 

  • Therefore the researcher can gain insight into the unique experience of the participant

  • This is a holistic approach, where the whole individual is considered

  • Thus, case studies are high in ecological validity

• Conducting a case study of an individual with an unusual, rare disorder or condition allows researchers to form conclusions as to how the majority of the population functions, e.g.,

  • The study of HM showed the effect on memory of brain damage due to hippocampal surgery

    • The lack of a hippocampus in HM (seen via MRI and then post-mortem examination) highlighted the importance of this brain structure in the formation of new memories

Limitations

• The findings from case studies only represent the person (or small group) who is the focus of the study

  • This means that they cannot be generalised to wider populations

• Case studies may suffer due to the relationship between the researcher and the participant

  • The researcher may begin to feel too close to the person they are studying, which could result in them losing their objectivity and possibly using bias in their reporting of the results

    • Any type of bias would impair the validity of the findings