AO1
The idiographic approach focuses on individuals and emphasises uniqueness favouring qualitative methods in research. The idiographic approach is qualitative as the focus is on gaining insights into human behaviour by studying unique individuals in depth as opposed to gaining quantitative data from many individuals and determining average characteristics. It employs qualitative methods such as unstructured interviews, case studies and thematic analysis. An example of the idiographic approach if from Freud as he uses case studies of patients to understand human behaviour eg Little Hans.
The nomothetic approach on the other hand seeks to formulate general laws of behaviour based on the study of groups and the use of statistical techniques (quantitative.) It attempts to summarise the differences between people through generalisations. An example of the nomothetic approach is from the biological approach which seeks to portray the basic principles of how the body, mind and brain work.
Behaviourist psychologists produced general laws of behaviour- classical and operant conditioning seeking one set of rules for both humans and non-humans.
AO3
The Idiographic approach criticised for not being scientific as it uses unscientific research methods meaning we are unable to make predictions and general laws. However it can be argued that they can provide a detailed picture which can then be used to generalise (e.g. case studies in memory). The nomothetic approach however is very scientific as we can establish cause and effect generating general laws of behaviour which can be used to predict human behaviour.
The idiographic approach is preferable as it focuses on the individual whereas the nomothetic approach has arguably lost sight of what it is to be human. Humanistic psychologists felt that there was too much emphasis on measurement in the nomothetic approach. However whilst the focus is on the individual the idiographic approach is time consuming as it is in terms of collecting large amounts of data about one person.