Does anything Emerge? CSS Interaction Task A review on the state of the art in the understanding, modelling and formal description of emergence

Does anything Emerge?CSS Interaction Task

A review on the state of the art in the understanding, modelling and formal

description of emergence

Why

Aims

• to define the broad directions which a research program on Emergence should follow in order to deepen our theoretical understanding

• to bring Emergence concepts and tools into the arsenal of physical, natural and social scientists

What has been done• Call for material/ideas/collaborations via CSS_Ideas

mailing list• Considerable reading• Production of a working draft• Preliminary session at the 2004 CSS workshop

• Submission of a short paper to the KES conference (Knowledge-Based & Intelligent Information & Engineering Systems, Melbourne

Sept 2005)

• Main workshop, May 05 • Manuscript Preparation

Actual outcomes• A better understanding of the concept –

I think so.. listen on.. • Document/Web site open to CSIRO and others,

http://www.per.marine.csiro.au/staff/Fabio.Boschetti/CSS_emergence.htm

• short paper to the KES conference http://www.per.marine.csiro.au/staff/Fabio.Boschetti/3054CO/papers

/emergence_kes_final.pdf • Review Paper

Research Program Paper under development

Interaction Outcomes• crucial input from Cosma Shalizi and Daniel Polani

• close interaction between 4 members (FB, Mikhail Prokopenko, IM, AMG) in draft preparation

• close interaction between 16 members at main workshop

• Strongly multidisciplinary approach (biologists, chemists, computer scientists, applied maths, physicists, social scientists, and engineers)

• Exposure to the “The Pacific Institute of Theoretical Physics (PITP)

workshop on ‘Emergence’, 15-18 May 2005, Vancouver, BC” http://pitp.physics.ubc.ca/archives/CWSS/emergence/talks.html

Review / Research Program Paper

Approach• Information Theoretic • Cosma Shalizi’s “The efficiency of prediction”• Difference between emergence, complexity and self

organization• How Cosma’s definition could be implemented and

tested on a set of real problems


Cosma Shalizi’s “The efficiency of prediction”

“The efficiency of prediction of a process is the ratio between its excess entropy and its statistical complexity, e =E/C.”

E=Excess Entropy• the mutual information between two adjacent semi-infinite blocks

of variables -> • measure of the apparent memory or structure in the system -> • we may think of it as the fraction of historical memory stored in the

process which does “useful work" in the form of telling us about the future.


Cosma Shalizi’s “The efficiency of prediction ”

“e =E/C ---- How to calculate E”

1

))((L

dd hLhE

))(

(limH

LHh

Ld

Excess Entropy

Entropy Density



“The efficiency of prediction of a process is the ratio between its excess entropy and its statistical complexity, e =E/C.”

C= Statistical Complexity

• Entropy of the process Casual States -> • We may think of it as a measure of the amount of memory required

for optimal prediction.


1) Generate a causal state machine (CSSR algorithm, for

example)

2) Calculate entropy of the e-machine

Cosma Shalizi’s “Ease of predictability”

“e =E/C ---- How to calculate C”


prediction optimalfor requiredmemory ofamount

blocks infinite-semibetween n informatio mutual

C

Ee


predict toisit difficult how

predict can much we how

C

Ee


Given 2 levels of representation, we say one level ‘emerges’ from the other if it has greater predictive efficiency.

prediction optimalfor requiredmemory ofamount

blocks infinite-semibetween n informatio mutual

C

Ee



What is good about it?

1) It is non trivial2) It removes ‘magic’ from the concept (‘cannot be explained’, ‘is

not displayed’, etc)3) it is computable (albeit in limited cases)4) it distinguishes Emergence from Complexity and Self

Organisation



• Complexity= amount of information necessary for optimal prediction

• Self-organisation = spontaneous increase of complexity in time

• Emergence = E/C• Adaptivity=Increase of Mutual Information between a

system and the environment


What might be missing?

1) Not always computable

2) Emergence/Complexity/Self-Organisation are different, but what is the relation between them?

3) How do we account creation of ‘novelty’ and ‘diversity’? (surprise effect)

4) How does Emergence arise?

5) Are there different classes of Emergence?



• Motivation • Justification for an information theoretical approach • Ordering of emergence phenomena • Drivers and conditions for Emergence • Detection of Emergence • Modelling of Emergence • Research agenda

– how to construct emergence – Designing desired emergence properties; – Mechanism for emergence – Boundaries – How we use it

Paper Organisation

What next?

• Finish the paper and submit• Possible relation to UD, Memes and generation of follow up IT?

(David Batten?)• Results, tools, insights feeding into CSS projects

– Network Theory IT– Model Structure

• Delineation of a research program– Detection– Design for emergence– The role of system boundaries– Mechanism for Emergence– How to use it

Some Conclusions

• Information Theoretic approach• Emergence as relation between levels of representations• Emergence as increase efficiency of prediction• Definition of a research program on the topic

Some Conclusions

• Did we interact? Yes• Did we learn something? Yes• Did we contribute something useful?

– We took a unpublished definition

– We challenged it

– We planned how to test it on real cases

– How to extend it to different disciplines

All material currently available at

http://www.per.marine.csiro.au/staff/Fabio.Boschetti/CSS_emergence.htm

Documents

Does anything Emerge? CSS Interaction Task A review on the state of the art in the understanding, modelling and formal description of emergence