Case studies are intensive analyses of an individual unit. Case studies are different from experiments, observations and survey in two different respects: 1) Their idiographic nature, in the respect that they involve making a detailed study of single individuals or instances of something for example a family. 2) The second aspect is it is qualitative data, as opposed to quantitative data. Whilst the numerical measurements are not excluded the emphasis is upon description rather than figures.
Case study methods have been used extensively in psychology for many many years. Amongst the well known users is Sigmund Freud. Freud and other psycho-analysts employed case studies in their compilation of case histories of the patients they treated. An example of one of Freud’s case studies is Little Hans, Hans was the son of one of Freud’s friends (a doctor who was interested in Freud’s work). Hans was terrified of horses and especially afraid of being bitten by one. Freud theorised that in his unconscious mind he had incestuous desires for his mother but was afraid that his father would find out and castrate him as punishment. On a conscious level he expressed his anxiety as a fear of horses which symbolised his father as of biting which symbolised his father. This was then backed with detailed evidence, for example he particularly feared white horses with blinkers and black around the mouth-his father had a black moustache and glasses. It is these case studies that derives theories of personality and the oedipus concept.
Some strengths of the case study method are the fact they are so detailed, case studies allow the study of all aspects of an individual case rather than just being concerned with a few measurable characteristics. There is a greater chance that insights might be gained into the nature of behaviour, which might well be missed in other methods of study. Furthermore the descriptions of qualitative data are another advantage, case studies are based more upon description and upon qualitative data, than upon measurement. It is therefore less likely to ignore areas of behaviour which cannot be easily measured.
As with any method of data collection there are also weaknesses. Firstly is the generalizability, because the case study method deals with only one or possibly a few individuals studied in great depth, it is not easy to generalise findings to other people. The results of a study of one individual are really only valid in the case of that individual. Great caution should be taken when generalising to other individuals. Secondly the subjectivity of case studies is a further disadvantage, because they are based on the analysis of qualitative rather than quantitative data, it is in the hands of researchers alone. They are also responsible for deciding what to include in their descriptions and what to omit. This makes it easy for the researchers to leave out what does not support his or her theory. An example of this again is Freud, he was the sole analyst, observer and interpreter of his own observations. It was therefore up to him to interpret what he observed in a way which would support his ideas about the oedipal concepts, which is a major criticism of his work.
Overall case studies are a very effective method of data collection that provide data that is very rich in description that explores areas of behaviour that quantitative data fails to account for however; information does need to be treated with caution when trying to generalise information.