Systems 550 ppt_art


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Systems 550 ppt_art

  1. 1. System Dynamics Preston Gales
  2. 2. Systems Thinking Systems Thinking is a way to look at complex systems. It is an approach to observing and analyzing complex organizations in a comprehensive manner: seeking to understand the structure, the interconnections between all of the components, and how changes in any one area will affect the whole system and its related parts over time.
  3. 3. Systems Thinking (cont.) What is a “system”? a system is "a collection of interacting elements that function together for some purpose" (Roberts et al. 1983, 5).
  4. 4. Key Systems Thinking Concepts Mental Models Our beliefs, assumptions, and ideas about how things work. Mental models are often hidden, even from ourselves. Dynamic System Systems, which change over time, are dynamic. Growth, decay, and oscillations are the fundamental patterns of systems. Change Over Time There are patterns in the world that we can understand, with a little effort. These patterns are usually generated by interconnectedness. Feedback The real world often operates in circular causality, not just cause and effect. Leverage How can I generate viable options and solve real problems in a complex and interconnected world?
  5. 5. Examples of systems thinking inaction In history class, students study the inter-dependent relationships between oppression, power, and rebellion in order to better understand the causes of various revolutions. In literature class, students use a computer simulation of the novel, “The Giver”, to discover the possible results of changes in the society represented in the story.” In the community, city planners use causal loop diagrams to study long-term, unintended consequences of a new policy. They consider potential effects throughout the system – not just in the immediate proximity. In science class, students graph the growth patterns over time of various populations in a pond and look for possible clues to understanding the extreme level of toxicity in the water
  6. 6. What is the relationship between SystemsThinking and System Dynamics? Dynamic systems are those that change over time. Organizations Companies Schools Government entities Systems thinking and dynamics look at exactly the same kind of systems from the same perspective. Systems thinking constructs the same causal loop diagrams, but it rarely takes the additional steps of constructing and testing a computer simulation model, and testing alternative policies in the model.
  7. 7. System Dynamics System dynamics is a methodology for studying and managing complex feedback systems, such as one finds in business and other social systems. While the word system has been applied to all sorts of situations, feedback is the differentiating descriptor here. Feedback refers to the situation of X affecting Y and Y in turn affecting X perhaps through a chain of causes and effects. One cannot study the link between X and Y and, independently, the link between Y and X and predict how the system will behave. Only the study of the whole system as a feedback system will lead to correct results.
  8. 8. System Dynamics (cont.)The methodology identify a problem develop a dynamic hypothesis to explain the cause of the problem build a computer simulation model of the system at the root of the problem test the model to be certain that it reproduces the behavior seen in the real world devise and test alternative policies in the model that alleviate the problem implement the solutionRarely is one able to proceed through these steps without reviewingand refining an earlier step. For instance, the first problem identifiedmay be only a symptom of a still greater problem.
  9. 9. System Dynamics (cont.) The field developed initially from the work of Jay W. Forrester. His book Industrial Dynamics (Forrester 1961) is still a significant statement of philosophy and methodology in the field. Since its publication, the span of applications has grown extensively and now encompasses work in: corporate planning and policy design public management and policy biological and medical modeling energy and the environment theory development in the natural and social sciences dynamic decision making complex nonlinear dynamics education
  10. 10. System Dynamics (cont.) Understanding Stocks and Flows The stock of goods is increased by restocking and depleted by customer purchases over time. The accumulation of water in a bathtub increases as water flows in through the faucet and decreases as water flows out through the drain. Money in a bank account increases with deposits and decreases with withdrawals. Populations of people and other species change over time through births and deaths. The number of passengers on a bus or train varies as people get on and off. Your weight depends on the calories you consume and burn off.
  11. 11. System Dynamics (cont.)
  12. 12. System Dynamics (cont.)STELLA® STELLA offers a practical way to dynamically visualize and communicate how complex systems and ideas really work. Modelers, teachers, students, and researchers use STELLA to explore and answer endless questions like: How does climate change influence an ecosystem over time? Would Hamlet’s fate have changed if he’d killed Claudius earlier? How do oil prices respond to shocks in supply and/or demand? What will happen when the ozone layer is gone? How do basic macroeconomic principles affect income and consumption?
  13. 13. Creating Models and ConductingExperiments Borneo Model Immigration Model Conduct experiments A.T. Kearney Distribution Modeler Conduct experiments
  14. 14. System Dynamics in Distance EducationIn 1983 Moore proposed a theory of distance educationthat defined distance in terms of the "responsiveness" of aneducational program to the learner, rather than in terms ofthe physical separation of the instructor and the learner.System dynamics was selected for conceptualizing therelationships among the key variables and for simulatingthe temporal dynamics (time-based variance) of suchinterrelationships. Analysis of the discourse between theinstructor and the learners provided the means ofmeasuring the variables under study and the raw data forsimulating the interrelationships of the variables. (Saba 1994)
  15. 15. System Dynamics in Distance Education(cont.) In 1980, Moore introduced the concept of transactional distance and defined it as a function of two variables, dialogue and structure (Moore, 1980). Dialogue is "the extent to which, in any educational program, the learner and educator are able to respond to each other"; Structure is "a measure of an educational programmes responsiveness to learners individual needs" (Moore 1983, 171). Transactional distance was defined as a function of the variance in dialogue and structure as they related to each other; from this perspective, "distance" in education is not determined by geographic proximity, but rather by the level and rate of dialogue and structure (Moore 1983; Saba 1988).
  16. 16. System Dynamics in Distance Education(cont.) In 1988, Saba proposed a system dynamics model to represent the relationship among these variables. This model assumed a systemic and dynamic relationship between dialogue and structure, and suggested how a learner and a teacher, by varying the rate of dialogue and structure, could control the level of transactional distance in a purposeful instructional setting. Causal Loop Diagram of Transactional Distance
  17. 17. System Dynamics in Distance Education(cont.)Transaction Distance is only one area where Systems Thinking and SystemsDynamics can be used.Coldeway (1988) suggested the use of system modeling in distance educationcontexts to study several interrelated variables such as: instructional content technological delivery system policies related to course completion the timing of course eventsAlso, based on Hawkridge and Robinsons (1982) analysis of internationaldistance education organizations, Saba and Twitchell (1988/89) developed asystem dynamics model that simulated the relationship of: available resources student population and attrition management instructional development production of instructional materials dissemination
  18. 18. System Dynamics in Distance Education(cont.) Distance education is a complex concept; its study requires, methodology that can accommodate data collected on several variables the analysis of their interrelationship over time Distance education is affected by the political, social, financial, and technological factors in its environment. System dynamics also provides for the study of interrelated variables over a period of time. The variables of transactional distance, dialogue and structure, are not static: they change over time depending on the interaction between an instructor and a learner.
  19. 19. The variables, or system components, aredefined as follows: dialogue is "the extent to which, in any educational program, learner and educator are able to respond to each other" (Moore 1983, 171). In other words, it is the extent of verbal interaction between the educator and the learner. Structure is "a measure of an educational programmes responsiveness to learners individual needs" (Moore 1983, 171) or the extent to which pace, sequence, feedback, and content are organized. Transactional distance is a function of the variance in dialogue and structure as they relate to each other; therefore, "distance" in education is not determined by geographic proximity, but by the level and rate of dialogue and structure (Moore 1983; Saba 1988). learner control is a dynamic variable changed by the dialogue (discourse) between learner and instructor and continuously influencing (altering) the overall dialogue of a telelesson in terms of objectives, feedback, pace, sequence, content, etc. (Garrison and Baynton 1989; Shearer 1991).
  20. 20. active indicates speech acts by the learner that show involvement in theinstructional transaction: providing information, requesting clarificationand elaboration, asking questions, providing feedback, and respondingto the instructors directives.passive indicates speech acts in which the learner responds by a simpleyes or no, or the absence of speech acts for long periods.Instructor control is a dynamic variable changed by the interactionbetween the instructor and learner and continuously influencing(altering) the structure of a lesson in terms of objectives, feedback,pace, sequence, content, indicates the instructors expository speech acts that provideguidance, information, and feedback; lead the learner by askingquestions; and respond to the learner by informative comments.indirect indicates the instructors inquisitive speech acts that requestclarification and elaboration from the learner, ask questions for thepurpose of clarification, respond to the learners inquiries, and providesupportive and corrective feedback.
  21. 21. Research Descriptive Empirical observation of systems in order to describe their status Observing and reporting • student/teacher behavior • Student/teacher interaction Prescriptive Testing results of empirical observation to derive principles for decision making, and problem solving
  22. 22. Research (cont.) Descriptive Prescriptive Instructor Script
  23. 23. Questions None? Ok good night!