framework or architecture within which numerous choices and adaptations must be made when a given application is required. A number of such architectures have been developed and provide examples of how one might proceed, although the field is still in its infancy, and it is too early to recommend a commitment to any one architectural framework (see Chapter 3).

Given the present state of the field at the unit level, it is probably most useful to view a human as a node in a set of overlaid networks that connect humans to each other in various ways, connect humans to tasks and resources, and so forth. One key idea is that these networks (1) contain information; (2) are adaptable; and (3) can be changed by orders, technology, or actions taken by individuals. Which linkages in the network are operable and which nodes (humans, technology, tasks) are involved will need to be specified in accordance with the specific military application. Some unit-level models can be thought of as architectures in which the user, at least in principle, can describe an application by specifying the nodes and linkages. Examples include the virtual design team (Levitt et al., 1994) and ORGAHEAD (Carley and Svoboda, 1996; Carley, forthcoming).

The panel cannot overemphasize how critical it is to develop situation-specific models within whatever general architecture is adopted. The situations and tasks faced by humans in military domains are highly complex and very specific. Any effective model of human cognition and behavior must be tailored to the demands of the particular case. In effect, the tailoring of the model substitutes for the history of training and knowledge by the individual (or unit), a history that incorporates both personal training and military doctrine.

At the unit level, several computational frameworks for representing teams or groups are emerging. These frameworks at worst supply a few primitives for constructing or breaking apart groups and aggregating behavior and at best facilitate the representation of formal structure, such as the hierarchy, the resource allocation structure, the communication structure, and unit-level procedures inherited by all team members. These frameworks provide only a general language for constructing models of how human groups perform tasks and what coordination and communication are necessary for pursuing those tasks. Representing actual units requires filling in these frameworks with details for a specific team, group, or unit and for a particular task.

The panel suggests that the Defense Modeling and Simulation Office (DMSO) encourage developers to employ a systematic methodology in developing human behavior representations. This methodology should include the following steps:

• Developers should employ interdisciplinary teams.