Case studies

• Case studies are detailed, in-depth and longitudinal
• To study 'a case' in psychology is to provide a detailed and in-dept analysis of an individual group, institution or event
• Case studies tend to take place over a long period of time (longitudinal) and may involve gathering data from family and friends of the individual as well as the person themselves
• Case studies often involve analysis of unusual individuals or events, such as a person with a rare disorder or the sequence of events that led to the 2011 London riots
• Case studies may also concentrate on more 'typical' cases, such as an elderly person's recollection of their childhood
• Researchers will construct a case study of the individual or event concerned, perhaps using interviews, observations, questionnaires or a combination of all of these. The data collected is usually qualitative
• Psychological tests may also be used to assess, for example, intelligence or personality. There are likely to produce qualitative data
• Strength: rich, detailed insight:

  Preferred to the more 'superficial' forms of data that might be collected (e.g. from an experiment assessing one aspect of behaviour at one moment in time). Such detail is likely to increase the validity of the data collected
• Strength: enables study of unusual behaviour:

  Some behaviours/conditions are very rare (e.g. HM) and cannot be studied using other methods. In addition some cases can help understanding of 'normal' functioning
• Limitation: prone to researcher bias

  Conclusions are based on the subjective interpretation of the researcher. This may reduce the validity of the study
• Limitation: participants' accounts may be biased

  Personal accounts (from participants and family) may be prone to inaccuracy/memory decay. Therefore evidence provided may be low in validity