Pål I. Davidsen

A comprehensive analytical approach for policy analysis of system dynamics models

Formal tools to link system dynamics models structure to the system modes of behavior have recently become available. In this paper, we aim to expand the use of these tools to perform the models policy analysis in a more structured and formal way than the exhaustive exploratory approaches used to date. We consider how a policy intervention (a parameter change) affects a particular behavior mode by affecting the gains of particular feedback loops as well as how it affects the presence of that mode in the variable of interest. The paper demonstrates the utility of considering both of these aspects since the analysis provides an assessment of the overall impact of a policy on a variable and explains why the impact occurs in terms of structural changes in the model. Particularly in the context of larger models, this method enables a much more efficient search for leverage policies, by ranking the influence of each model parameter without the need for multiple simulation experiments.

Understanding the dynamics of electricity supply, resources and pollution: Pakistan's case

To meet the compelling demand for electricity, the government of Pakistan introduced reforms in 1990–1991 that provide incentives for private sector investments, particularly in the electric power industry. In response to these incentives, most of the independent power producers (IPPs) offers included oil, coal and/or gas power plants. Hydroelectric generation, despite its rich resource base in the country, did not gain much attraction. This research provides an assessment of the existing policy subject to the constraints of environment concerns and available, but limited, resources. A dynamic simulation model that captures the dynamics of the sectors underlying the electricity system is built using system dynamics methodology. The policy assessment has been carried out in a three-dimensional context: the electricity supply; the resource import dependency; and the evolution of CO2 emissions. This research finds that the unchanged prolongation of the existing policy seems to effectively attract IPPs investments but not without potentially adverse consequences for the environment and the economy.

Modeling the estimation of petroleum resources in the United States

Estimates of ultimate recoverable petroleum resources in the lower 48 states have increased since 1910, but peaked in the 1960s and have since declined by over 50%. The apparent tendency of the estimates to overshoot their targets raises questions about the rationality and utility of estimation strategies. This paper describes a simulation-based study of the petroleum life cycle in the United States undertaken to evaluate different resource estimation techniques. Protocols for the Hubbert life cycle and USGS geologic analogy methods are developed and applied to synthetic data generated by the simulation model. It is shown that the Hubbert method is quite accurate, with a tendency to underestimate the ultimate recoverable resource somewhat, while the simulated geologic analogy estimates overshoot the resource base quite dramatically. Analysis of the model pinpoints the sources of error and suggests way to improve resource estimation strategies.

Issues in the design and use of system-dynamics-based interactive learning environments

The author presents an overview of the topics covered by the articles in this special issue on system-dynamics-based interactive learning environments (ILEs). The article shows how a system-dynamics-based ILE is being designed to portray the intimate relationship between structure and dynamic behavior in complex domains. The complexity and need for a structural foundation for the interpretation of behavior create the following challenges: to associate behavior to underlying structure; to explicitly represent the integration processes, including delays (lags), that drive dynamic behavior; to trace the various feedback structures so as to identify what determines their relative contribution to the overall behavior; to facilitate the strengthening and weakening of such loops as a basis for policy design; to represent any nonlinearity that might exist and map each operating point onto them so as to identify variations in dynamic sensitivity; to effectively portray the significance of uncertainty and vagueness; and last but not least, to put it all together.

Creating engaging courseware using system dynamics

Abstract There is much discussion in the instructional technology literature concerning the importance for engaging courseware, especially in contrast to page-turning courseware. While we believe that there is a useful place for simple, page-turning courseware (e.g., in tutorials accompanying software products, for overview introductions to a topic, etc.), we agree that for more sophisticated and complex learning situations the key to a successful learning environment is the degree to which learners are cognitively engaged with the subject matter. System dynamics has been shown to be an effective tool in managing (representing, modeling, and comprehending) the complexities of domains that involve complex structures, especially those characterized by feedback loops, delays, and uncertainty (Forrester, 1961, 1985, 1992; Senge, 1990). In this paper, we shall suggest a framework for using system dynamic tools and technologies as the basis for constructing highly engaging learning environments.

A Blend of Planning and Learning: Simplifying a Simulation Model of National Development

Simulation models provide decision support to long-term planning processes. The Bergen Learning Environment for National Development (BLEND) is a game based on a simplified version of Millennium Institutes Threshold 21 model (T21) that sensitizes policy makers in sub-Saharan African nations to the need for simulation-based decision support. The simplification eliminates or aggregates details about individual policy sectors and maintains cross-sector relationships. Validation indicates that the full and the simplified T21 model generate very similar behavior patterns for a wide range of policy scenarios. Pilot tests demonstrate that the simplified T21 model contributes to the learning goals of BLEND. The debriefing employs causal loop diagrams and simulation for structural explanations of the behavior observed during the game. BLEND workshops with repeated runs of the game, full debriefing sessions and different formats of instructional support will contribute further to research on dynamic decision making and learning about tasks with great complexity.

Effect of Prior Exploration as an Instructional Strategy for System Dynamics

In complex simulation-based learning environments, participants’ learning and performance may suffer due to demands on their cognitive processing, their struggle to develop adequate mental models, failure to transfer what is learned to subsequent learning or activities, and fear of failure. This study investigates an instructional strategy addressing those four problems, which we call prior exploration strategy. It was implemented in a simulation requiring participants to optimize a developing nation’s per capita income. The prior exploration strategy allows participants to manipulate and see the results of a simulation model in practice mode before they manage a similar simulation in a more final mode. The strategy was assessed in an experiment comparing participants using the prior exploration strategy with participants studying equivalent content in a non-exploratory fashion. The dependent variables were performance within the simulation and improvement of participants’ understanding. The prior exploration strategy significantly improved participants’ performance, as measured by per capita income. It also significantly improved some aspects of the participants’ understanding (e.g., their understanding of the nation’s debt accumulation), but not others (e.g., their understanding of the need to balance the nation’s health, education, and infrastructure investments; those that appear to have complex interrelations).

Applying system dynamics to courseware development

The general purpose of the work reported here is to extend and validate system dynamics technologies for their use in managing the complexities and risks of large scale, courseware development projects. Courseware refers to a variety of computer-based instructional materials used for the purpose of creating effective learning environments. While the costs for computer hardware are generally declining, new hardware and software technologies are appearing with a frequency that makes it a serious challenge to hire and train designers, developers and project managers and to plan and produce computer-based instructional materials that are both effective (in terms of learning) and efficient (in terms of costs and technology utilization).

Integrating Systems Thinking and Instructional Science

This chapter presents the young discipline of systems thinking, that is, study of structure, behavior and management of complex systems. We approach systems thinking from two different, though supplementary angles: modeling and simulation (system dynamics), and cognitive psychology of decision making in complex systems. We argue that progress in management of systems requires that system dynamics, cognitive psychology, learning theory and simulation-based instructional design be combined through a framework for automation of instructional system development. We expect this approach to produce insights of general validity to the field of ISD at large.

Critical Reflections on System Dynamics and Simulation/Gaming

Purpose. This article critically discusses the contributions in this symposium and the progress in the fields of system dynamics and interactive learning environments. Two Perspectives. For this purpose, the article uses two different perspectives. One perspective is system dynamics or model-based policy analysis and design. The other perspective is the learning sciences, that is, the theories and principles of learning. Commentaries. With these two perspectives in mind, this article reflects on each of the eight contributions to this symposium and gives critiques and suggestions. Recommendation. The results and insights generated by these contributions suggest that the greatest need for future research on system dynamics and its contribution to simulation-gaming is demonstration of improvements in learning and performance.