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- The Problem of Learning
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Problemistics - Problémistique - Problemistica
The Art & Craft of Problem Dealing
Model
Definition (Abraham Kaplan)
Definition (Encyclopaedia of World Problems and Human Potential)
Classification (Russell L. Ackoff, C. W. Churchman, E. Leonard Arnoff)
Classification (Thomas A. Markus)
Models: classifications (C. H. Waddington)
Classifications (Encyclopaedia of World Problems and Human Potential)
Function (Russell L. Ackoff, C. W. Churchman, E. Leonard Arnoff)
Function (Abraham Kaplan)
Functions (F. de P. Hanika)
Functions (C. H. Waddington)
Functions (Fremont E. Kast and James E. Rosenzweig)
Features (Russell L. Ackoff and Fred E. Emery)
[1964] Abraham Kaplan, The Conduct of Inquiry. Methodology for Behavioural Science, Chandler Publishing Company, Scranton, Pennsylvania
"Broadly speaking, we may say that any system A is a model of a system B if the study of A is useful for the understanding of B without regard to any direct or indirect causal connection between A and B."
“... models are isomorphs of one another. Both systems have the same structure, in the sense that whenever a relation holds between two elements of one system a corresponding relation holds between the corresponding elements of the other system.” (Chapter VII, p. 263)
[1986, Second Edition] Encyclopaedia of World Problems and Human Potential, Union of International Associations eds., K. G. Saur, München
Model. "1. In the broadest sense, a model is simply a figurative or symbolic representation of something else. In order to produce information, a symbolic model is usually a verbal or mathematical expression describing a set of relationships in a precise manner. It can be useful simply to explain or describe something, or it can be used to predict actions and events."
"2. An ordered set of assumptions about a complex system. It is an attempt to understand some aspect of the infinitely varied world by selecting from perceptions and past experiences a set of general observations, applicable to the problem at hand."
"3. A theoretical projection in detail of a possible system of human relationships (e.g. in economics, politics, or psychology)." (KC0640)
[1964, First published 1957] Russell L.Ackoff, C. West Churchman and E. Leonard Arnoff, Introduction to Operations Research, John Wiley & Sons, New York
"We shall distinguish three types of model:
1) an iconic model pictorially or visually represents certain aspects of a system (as does a photograph or model airplane);
2) an analogue model employs one set of properties to represent some other set of properties which the system being studied possesses (e.g. for certain purposes, the flow of water through pipes may be taken as an analogue of the 'flow' of electricity in wires);
3) a symbolic model is one which employs symbols to designate properties of the system under study (by means of a mathematical equation or set of such equations)." (Chapter 7, p. 158)
[1969] Thomas A. Markus, The role of building performance measurement and appraisal in design methods, in Geoffrey Broadbent & Anthony Ward, eds., Design Methods in Architecture, Architectural Association Paper nº 14, Lund Humphries, London
"Descriptive Models. The prime function is to portray the relationships that are seen to exist in a situation. For instance, models of circulation movement showing the relationship of corridor and lift dimensions to flow capacities."
"Predictive Models. Given a set of relationships (descriptive models), if one variable can be predicted and the relationship holds, then the other variable(s) can be predicted. For instance, for a given size and speed of lift the waiting time (under a specified arrival pattern) can be predicted."
"Decision Models. From a set of predictive models (alternative solutions) one must be chosen. This requires the use of a criterion. When this is done analytically to derive an optimum ... the optimization procedure involves building this decision model." (pp. 116-117)
[1977] C. H. Waddington, Tools for Thought, Jonathan Cape, London
“Models may be used to describe a situation at a given point in time. These are called descriptive models.
Or, if they contain time-dependent variables, they may be used to predict what happens at some future time. These are called predictive models." (Chapter 11, p. 207)
[1986, Second Edition] Encyclopaedia of World Problems and Human Potential, Union of International Associations eds., K. G. Saur, München
"Models can be distinguished and classified in many ways, including:
- By function: descriptive, predictive, and normative models.
- By time reference: static and dynamic models.
- By uncertainty reference: deterministic, probabilistic, and game models.
- By generality: general, and specialized models." (KC0640)
[1964. First piblished 1957] Russell L.Ackoff, C. West Churchman and E. Leonard Arnoff, Introduction to Operations Research, John Wiley & Sons, New York
"The iconic model is usually the simplest to conceive and the most specific and concrete. Its function is generally descriptive rather than explanatory, i.e. it seldom reveals causal relationships."
"The symbolic model is usually the most difficult to conceive and the most general and abstract. Its function is more often explanatory than descriptive. Accordingly, it is ordinarily well suited to the prediction or determination of effects of changes on the actual system."
"Analogues fall between iconic and symbolic models in both respects." (Chapter 7, p. 158)
[1964] Abraham Kaplan, The Conduct of Inquiry. Methodology for Behavioural Science, Chandler Publishing Company, Scranton, Pennsylvania
"... a model might be said to be the embodiment of a structural analogy.
The embodiment might be in a set of symbols (that is, in the conceptual structure they specify), or else in some actual physical system. Such models might be called analogues, as a generic term for both conceptual and physical isomorphs.
These may be distinguished as semantical and physical models." (pp. 266-267)
"By far the oldest and most widely used type of isomorph is the physical model." "Being more accessible and manipulable, it is well suited to the purposes of pedagogy - as exemplified by the planetarium, which may model the solar system or the cosmos."
"The semantic model is a symbolic or conceptual analogue. By providing a clearly specified structure, it allows for application of statistics and other mathematical tools." (p. 273)
[1972, First published 1965] F. de P. Hanika, New Thinking in Management, Heinemann, London
“In the social sciences models serve diagnostic (or explanatory) as well as descriptive purposes.”
"Developing a model of a problem situation forces us to clarify the relationships between its constituent components."
Models are generally defined as replicas which closely reproduce or reflect the relationships and controlling properties of a situation or process." (Chapter 2, p. 19)
[1977] C. H. Waddington, Tools for Thought, Jonathan Cape, London
“When faced with the problem of exploring the possible ways in which some situation might evolve in the future, one of the most highly developed tool that an analyst has is to set up an analogue of the real world which may then be manipulated to discover how it works under new conditions. This analogue or model represents, in a simplified form, the processes of some aspect of the real world. Operating the model by manipulation of its elements by means of humans, computers, or both, in order to see how it reacts (and by analogy how the real world should react), is termed simulation.” (Chapter 11, p. 206)
[1979, Third Edition] Fremont E. Kast and James E. Rosenzweig, Organization and Management, McGraw-Hill
“Constructing a model is a common technique of abstraction and simplification for studying the characteristics or behavioural aspects of objects or systems under varying conditions. The model itself is usually a representation of objects, events, processes, or systems. Manipulation of the model is used to test the impact that proposed changes (in one or more components) will have on the system as a whole.” (Chapter 15, p. 372)
[1972] Russell L. Ackoff and Fred E. Emery, On Purposeful Systems, Tavistock Publications, London.
“An individual’s model of a choice situation is his representation of it.”
“A model includes only those properties that either the individual believes have an effect on the outcomes of interest (and therefore are relevant), or that he is doubtful about and wants to investigate further.”
(Chapter II, pp. 79-80)