The field of judgment and decision making is fragmented and researchers may not be aware of the wider context in which the approaches they predominately adopt can be placed, or the relative utility of different approaches to studying human judgment. The present special issue intends to: present, with empirical examples, four different approaches to modelling human judgment; compare the portrayal of the nature of human judgment using these approaches, for example in terms of the predictability of human judgment, the use of information, and human judges' ability to describe and understand the models of their judgment data; discuss the relative merits and limitations of these approaches in terms of their ability to describe and predict human judgment behaviour, and discuss the compatibility of these approaches. Each paper will characterise the research carried out in a tradition and will describe recent research using the technique to modelling human judgment and decision making. The four approaches are: static or structural, dynamic, process tracing and simple heuristics. Two discussions will each pull together the work of these different "groups" of researchers. Nigel Harvey will discuss the relative merits and limitations of each approach as they have been presented by the authors. John Maule will discuss the more general issues that need to be taken into account when choosing between different approaches.