Systems theory
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Transcript of Systems theory
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
Systems theory
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
Papers: Klir, G.J. [2001]. Facets of systems Science. Springer. Chapters: 1 and 2 Rosen, R. [1986]. "Some comments on systems and system theory". Int. J.
of General Systems, 13: 1—3. Ashby, W.R.[1956]. An Introduction to Cybernetics, Chapman & Hall, London,
Chapter 1.
This week
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
Informatics:a possible parsing
X-Informatics or Computational X
Informatics
Computer Science
Complex Systems
Data & Search
Data Mining
HCID
Social Informatics
Security
Bio-
Chem-
Geo-
Music-
Health-
towards problem solving beyond computing into the natural and social synthesis of information technology
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
MACY meetings:Norbert Wiener and Arturo Rosenblueth:
Goal-directed behavior and negative feedback (control) Homeostasis and circular causality
In machines and biology Automata Theory Communication
The fundamental idea is the message, even though the message may not be sent by man and the fundamental element of the message is the decision” (Norbert Wiener)
Information and Communication Theory Natural semiotics (McCulloch and others later get into Peircean Semiotics) “functional equivalence” of systems (general systems) Bio-inspired mathematics and engineering and computing/mechanism-inspired biology and
social science
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
What is systems science?a science of relations and a lesson for informatics?
How to define an interdisciplinary field “systems science is what systems scientists do” “systems science is that field of scientific inquiry whose objects of study are
systems” What are systems? (George Klir)
“a set or arrangement of things so related or connected as to form a unity or organic whole” (Webster’s New World Dictionary)
Systemhood properties of nature Robert Rosen
Systems depends on a specific adjective: thinghood (cf. “setness” or cardinality)
Systemhood: properties of arrangements of items, independent of the items
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
What is a system?(slightly more formally)
S = (T, R) S: a System T: a set of things
thinghood R: a (or set of) relation(s)
Systemhood Examples
Collections of books or music files Are sets
But organizations of such sets are systems E.g. alphabetically, chronologically, typologically, etc.
I501 – Introduction to Informatics
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Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
What is a system, cont’d...
Organizational properties defined by relations Same relation can be applied to different sets of objects or things Systems science deals with organizational properties of systems
independently of the items Wiener’s functional equivalences Separation only relevant for complex systems
What about Informatics? Can we separate what pertains to informatics and what pertains to thinghood-
based dsciplines?
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
Systems science: cross-disciplinary
It is a scientific endeavor that contains A body of knowledge~ (complex) relations A methodology to acquire new knowledg, solve problems A metamethodology: Methods and problem-solving capabilities are characterized and
critically examined Knowledge and methodology
Applicable to thinghood-based science Equivalent organizations from different fields can be studied as a whole rather than as a
subproblems in a specific field Offers unifying principles in partnership with traditional science
Two-dimensional science for the information or postindustrial age Examples
Control, Communication, information, dynamical systems, chaos, evolutionary systems, scale-free networks, modularity, robustness, information networks, search, Etc.
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
What is a system: more formally
S = (T, R) S: a System T = {A1, A2, …, An}
A family of sets of things: thinghood Cartesian Product
Set of all possible associations of elements from each set, i.e. all n-tuples
{A1 × A2 × … × An} R: a (or set of) relation(s)
Subset of the Cartesian product of some set of sets: Systemhood
Many relations R can be defined on the same T
From Klir [2001]
I501 – Introduction to Informatics
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Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
Types of relations
Equivalence: (~exact same features) Reflexive, Symmetric, transitive
Compatibility: (~synonyms) Reflexive, symmetric
Partial orderings: Reflective, anti-symmetric, transitive (t1 >= t2)
Strict orderings: anti-reflexive, Antisymmetric, transitive (t1 > t2)
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
Equivalence classes
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
Equivalence classes
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
Equivalence classes
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
Compatibility classes
Not different in more than 2 categories.
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
An example in bibliometrics: the scientific social system
System: science Things: scientists Relation: compatibility relation, e.g. co-authorship
S = (T,R)
T = {t1,t2, …, tk}R is subset or equal to T x T, R = {(ti,tj), …}
defined as: has co-authored a papercompatibility relation:reflexive, symmetric, non necessarily transitive
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
An example in bibliometrics: the scientific social system
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
An example in bibliometrics: the scientific social system
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
An example in bibliometrics: the scientific social system
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
An example in bibliometrics: the scientific social system
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
An example in bibliometrics: the scientific social system
We have defined our system now.
In fact, equivalence class of systems?- set of systems for which isomorphic relation establishes equivalence such that systemhood properties are preserved, for different set of things
What would be in equivalence class of this system? article networks, social networks, epidemiological networks?
Scientific process of analysis and modeling continues, but now focused on system properties of equivalence class, not so much thinghood.
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
Interpretation-free relations
From Klir [2001]
Class of isomorphic abstracted systems• Systemhood properties are totally preserved under some suitable transformation from the set of things of one system into the set of things from the other system• Equivalence relation: Reflexive, symmetric, and transitive• Divide the space of possible systems (relations) into equivalent classes
Devoid of any interpretation!• General systems• Canonical examples of equivalence classes
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
Constructivism vs. realism
Issue situated in epistemology:“branch of philosophy concerned with the nature and scope (limitations) of knowledge.”
Systems: two positions:1) exist independent of observer and discovered from nature:
realism2) system do not exist in the real word, independent from of the
human mind, but created by the decisions and distinctions that scientists make: constructivism
OK, but how to choose between such constructions?Francis Heylighen (evolutinary perspective):
- objective: distinctiveness ("difference that makes a difference”), invariance (to point of view, time, persons), controllability
- subjective: utility, coherence, complexity, etc- intersubjective: formality, conformity, infectiousnessetc
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
Immersed in scientific currents of the last decade
http://www.scribd.com/doc/14805983/Streams-Systemic-Thinking
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
10 miles up:
http://www.art-sciencefactory.com/complexity-map_feb09.html
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
Discussion questions
Klir, Facets of Systems Science:- Think of two isomorphic systems based on partial orderings in your domain of interest- “constructivism”: summarize in your own words and speculate on relevance to education
Rosen, comments on cybernetics and systems science- Margaret Thatcher famously said: “There's no such thing as society... only individuals and families.” Frame that statement in Rosen’s comments on systems science.
Ashby, introduction to cyberneticsAshby gives an example of the development of a rabbit ovum. Discuss the cybernetics point of view and juxtapose it to what Ashby calls the “older point of view
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
Discussion questions
The importance of stupidity:
http://matt.might.net/articles/phd-school-in-pictures/
I501 – Introduction to Informatics
[email protected]://informatics.indiana.edu/jbollen/I501
Informatics and computing
Lecture 3 – Fall 2011
Informatics and computing
Next lecture: September 28
Complexity Lazebnik, Y [2002]. "Can a biologist fix a radio?--Or, what I learned
while studying apoptosis". Cancer Cell, 2(3):179-182. Simon, H.A. [1962]. "The Architecture of Complexity". Proceedings
of the American Philosophical Society, 106: pp. 467-482. Klir, G.J. [2001]. Facets of systems Science. Springer. Chapters: 3,
8, and 11. September 28
Note: September 19 we will have no readings – postponed until September 28