As cognitive architectures move to account for increasingly complex real-world tasks, one of the most pressing challenges involves understanding and modeling human multitasking. Although a number of existing models now perform multitasking in real-world scenarios, these models typically employ customized executives that schedule tasks for the…

Berger and his colleagues argue that collective validation (i.e., group members' corroboration of deferential behavior) is an important source of legitimacy in informal task groups. This invites the question "What causes collective validation?" Drawing from Simmel and Blau in particular, I develop an explanation of collective validation that…

The increasing complexity of human body models enabled by advances in diagnostic imaging, computing, and growing knowledge calls for the development of a new generation of systems for intelligent exploration of these models. Here, we introduce a novel paradigm for the exploration of digital body models illustrating cerebral vasculature. It enables…

This paper introduces a hardware and software independent model for producing educational computer simulation environments. The model, which is based on the results of 32 studies of educational computer simulations program production, implies that educational computer simulation environments are specified, constructed, tested, implemented, and…

The concept of a qualitative model provides a unifying perspective for understanding how expert systems differ from conventional programs. Knowledge bases contain qualitative models of systems in the world, that is, primarily non-numeric descriptions that provide a basis for explaining and predicting behavior and formulating action plans. The…

A simulation model of episodic memory, MINERVA Z, is applied to the learning of concepts, as represented by the schema-abstraction task. The model successfully predicts basic findings from the scheme-abstraction literature, including some that have been cited as evidence against exemplary theories of concepts. (Author/LMO)

A model of information processing has been developed that combines concepts from the study of attention and the study of problem solving. The model has been realized as a computer program and used to simulate a variety of phenomena from the attention and performance literature. (Author/LMO)

Describes a model for the workload of a full text retrieval system and of a simulation model for a version of an existing system called Full/Text. The effectiveness of various data caching strategies using the 2 models are explored, and the impact of various parameters on the strategies are evaluated. (13 references) (LRW)

Discusses the extent to which computers can understand natural language. Considers assertions that computers can be described as literate, and considers more generally the purpose of designing machines which perform like humans. (RS)

Provides commentaries on professional and personal experiences in the development of simulations in the study of international affairs. Describes the evolution in Simulated International Processes projects from a person-machine format to an all-computer simulation. Discusses work with the military, field work, teaching experiences, difficulties,…

Explores the use of computer simulation/modeling programs for teaching a variety of science concepts. (Author/CCM)

Extends the modeling system presented in Part I. This model is applied to two widely diverse educational processes: "Student Actions" and "Do Homework Problem." Its computational syntax imposes completeness criteria on the modeling and its uniformity. (AIM)

Assesses desktop-computer models that rotate in virtual three-dimensional space. Compares spatial learning with a computer carpal-bone model horizontally rotating at 10-degree views with the same model rotating at 90-degree views. (Author/CCM)

Type I error rates for PARSCALE's fit statistic were examined. Data were generated to fit the partial credit or graded response model, with test lengths of 10 or 20 items. The ability distribution was simulated to be either normal or uniform. Type I error rates were inflated for the shorter test length and, for the graded-response model, also for…

Disturbance-generated biomass results from endogenous and exogenous natural and cultural disturbances that affect the health and productivity of forest ecosystems. These disturbances can create large quantities of plant biomass on predictable cycles. A systems analysis model has been developed to quantify aspects of system capacities (harvest,…