Idiographic and nomothetic approaches to psychological investigation.

What this dot point is asking

AQA wants you to explain the idiographic and nomothetic approaches, with examples and evaluation. The exam skill is to distinguish the two by their focus and methods, to give examples from the approaches you have studied, and to argue that they are complementary rather than opposed.

The two approaches

The two terms come from the Greek: idiographic from "idios" (private, personal) and nomothetic from "nomos" (law). The idiographic approach treats each person as a unique individual and aims for a complete, in-depth understanding of that particular case, so it favours qualitative methods such as case studies, unstructured interviews and analysis of personal documents. The humanistic and psychodynamic approaches are largely idiographic; Freud built his entire theory partly from detailed case studies such as Little Hans. The nomothetic approach instead studies large numbers of people in order to formulate general laws, norms and principles that apply across the population, so it favours quantitative, scientific methods such as controlled experiments, correlations and standardised psychometric tests. The behaviourist approach (laws of conditioning) and the biological approach (general physiological principles) are nomothetic. Locating the approaches you have studied on this dimension is a quick way to generate evaluation points.

Evaluating the two approaches turns on the trade-off between depth and breadth. The nomothetic approach has the strength of scientific rigour: its objective, standardised methods are replicable, allow statistical testing, and support prediction and generalisation, which is why it is regarded as more scientific. Its weakness is that the individual can be lost, becoming little more than a set of scores or a statistic, so that the predictions tell us nothing about a particular person's experience. The idiographic approach has the opposite profile: it provides a rich, complete and meaningful picture of the individual that can generate new hypotheses, but its reliance on small samples and subjective interpretation makes it hard to generalise and difficult to replicate, raising concerns about scientific status. The conclusion examiners reward is that the approaches are complementary rather than rivals: detailed idiographic cases can suggest and challenge general nomothetic laws, and a complete psychology needs both, as the study of the rare case of HM both illuminated one individual and contributed to general theories of memory.