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Laws, tradeoffs and theorems

Many of these are documented in Beyond Simon’s Slice: Five Fundamental Trade-Offs that Bound the Performance of Macrocognitive Work Systems by Hoffman and Woods.

  • Laws
    • Law of fluency
    • Law of stretched systems
    • Law of requisite variety
    • Laws of the adaptive universe
    • Law of coordinative entropy
    • Mr. Weasley's Law
    • The Law of the Kludge
    • First law of cooperative systems
    • (Robin) Murphy's Law
  • Tradeoffs
    • Efficiency-thoroughness tradeoff
    • Optimality-brittleness tradeoff
  • Theorems
    • Theorems of graceful extensibility

Laws

Law of fluency

Well-adapted cognitive work occurs with a facility that belies the difficulty of resolving demands and balancing dilemmas

Source: Beyond Simon’s Slice: Five Fundamental Trade-Offs that Bound the Performance of Macrocognitive Work Systems

Law of stretched systems

Every system is stretched to operate at its capacity.

Sources:

This law is attributed to Lawrence Hirschhorn, and has been popularized by David Woods and Richard Cook.

Law of requisite variety

The larger the variety of actions available to a control system, the larger the variety of perturbations it is able to compensate.

This is also called the first law of cybernetics or Ashby's law.

Source: http://pespmc1.vub.ac.be/REQVAR.html

Laws of the adaptive universe

  • Resources are finite
  • Surprise is fundamental
  • Change never stops

Source: http://csel.org.ohio-state.edu/ResilienceEngineering.html

Law of coordinative entropy

Coordination costs, continuously.

Source: Beyond Simon’s Slice: Five Fundamental Trade-Offs that Bound the Performance of Macrocognitive Work Systems

Law of systems as surrogates

Technology reflects the stances, agendas, and goals of those who design and deploy the technology.

Source: Beyond Simon’s Slice: Five Fundamental Trade-Offs that Bound the Performance of Macrocognitive Work Systems

Mr. Weasley's Law

Never trust anything that can think for itself if you can’t see where it keeps its brain.

Source: Beyond Simon’s Slice: Five Fundamental Trade-Offs that Bound the Performance of Macrocognitive Work Systems

The Law of the Kludge

Work systems always require workarounds, with resultant kludges that attempt to bridge the gap between the original design objectives and current realities or to reconcile conflicting goals among workers.

Source: Beyond Simon’s Slice: Five Fundamental Trade-Offs that Bound the Performance of Macrocognitive Work Systems

First law of cooperative systems

It's not cooperation, if either you do it all or I do it all.

Source: David Woods. Not sure where he first wrote this, but it's referenced in Cognitive Systems Engineering: The Future for a Changing World

(Robin) Murphy's Law

Any deployment of robotic systems will fall short of the target level of autonomy, creating or exacerbating a shortfall in mechanisms for coordination with human stakeholders.

Source: This is mentioned in Joint Cognitive Systems: Patterns in Cogntive Systems Engineering, Chapter 10 (Automation Surprises).

Tradeoffs

Optimality vs. resilience

The pursuit of increases in optimality with respect to some criteria guarantees an increase in brittleness with respect to changes or variations that fall outside of those criteria.

Described in Beyond Simon's Slice as:

  • bounded ecology
  • optimality-resilience of adaptive capacity trade-off

Efficiency vs. thoroughness

People (and organisations) as part of their activities frequently – or always – have to make a trade-off between the resources (primarily time and effort) they spend on preparing to do something and the resources (primarily time and effort) they spend on doing it.

Described in Beyond Simon's Slice as:

  • bounded cognizance
  • efficiency-thoroughness of situated plans trade-off

Source: http://erikhollnagel.com/ideas/etto-principle/index.html

Revelation vs. reflection

Because every perspective reveals some details and hides others, we gain an advantage from reflecting on different perspectives. But this reflection has a cost, it takes effort.

(The text itself doesn't describe "revelation", but my sense is that this is an explore/exploit style tradeoff, where we have to trade off going broader on perspectives with going deeper in a specific perspective).

Described in Beyond Simon's Slice as:

  • bounded perspectives
  • revelation-reflection on perspectives trade-off

Acute goal vs. chronic goal

There are ongoing (chronic) goals that we are always responsible for (e.g., safety), but we often face some shorter term deadline (acute) that demands more of our attention.

Described in Beyond Simon's Slice as:

  • bounded responsibility
  • acute-chronic goal responsibility trade-off

Concentrated action vs. distributed action

Distributing autonomy allows systems to act more quickly, but it makes synchronization across actions more difficult.

Described in Beyond Simon's Slice as:

  • bounded effectiveness
  • concentrated-distributed action trade-off

Theorems

Theorems of graceful extensibility

  • UAB stands for unit of adaptive behavior
  • CfM stands for capacity for manoeuvre
  1. Adaptive capacity is finite
  2. Events will produce demands that challenge boundaries on the adaptive capacity of any UAB
  3. Adaptive capacities are regulated to manage the risk of saturating CfM
  4. No UAB can have sufficient ability to regulate CfM to manage the risk of saturation alone
  5. Some UABs monitor and regulate the CfM of other UABs in response to changes in the risk of saturation
  6. Adaptive capacity is the potential for adjusting patterns of action to handle future situations, events, opportunities and disruptions
  7. Performance of a UAB as it approaches saturation is different from the performance of that UAB when it operates far from saturation
  8. All UABs are local
  9. There are bounds on the perspective any UAB, but these limits are overcome by shifts and contrasts over multiple perspectives.
  10. Reflective systems risk mis-calbiration

Source: The Theory of Graceful Extensibility: Basic rules that govern adaptive systems