Re: Central Control

[Bill Barowy <bill_barowy@terc.edu>]

David,


I'd like to pose a counter-example to your statement, or perhaps it is an
opportunity to refine my understanding of global knowledge:

>In research that we are doing related to emergent algorithms, we consider
>global visibility on a par with central control and generally do not
>consider algorithms that depend on either.  Global visibility, however, is
>much easier to distinguish than is central control.  Put another way, any
>control that depends on global knowledge of the state of the system as
>whole, should be considered central control.

Never having studied 'central control',  I'll offer some reflections
nevertheless.  It seems that central control can also depend upon layered
knowledge of the system - take for example a CEO in charge of an
institution, who holds little _global_ knowledge of the state of the
system, but instead relies upon the layers of control below to have
knowledge of activity within their purview.   The layers of control in this
case are the different levels of approval for taking certain actions
(mostly expenditure related).  The CEO's knowledge does not have to include
information about what is happening everywhere, all the time.  The CEO's
does have knowledge, however, that control at a lower level can be trusted
or controlled per se.  Perhaps this is one place where centralized systems
break down.  So for example, at TERC project directors have approval
authority for x dollars, cluster leaders have approval authority for y
dollars, where y>x, etc...  Project directors also coordinate the
day-to-day decisions of project teams to align them with project goals.

In star-logo this might be interpreted as turtles who have the ability to
oversee and override the behavior of a finite number of other turtles -
quite possibly examining the other turtles code and modifying it.  The
controlling turtles do not know the details of the 'decisions' each
individual turtle makes, but oversee the general behavior of the turtles.
This example extends, I think, to Mark Guzdials students who are learning
C++.  At a higher level, the students per se can be considered the central
control - although this level might be removed by students programming in
teams.





Bill Barowy, Senior Scientist
TERC, 2067 Massachusetts Ave, Cambridge, MA  02140
Phone: 617 -873-9606 / Fax: 617-349-3535 / Email: bill_barowy@terc.edu
- ------------
TERC is a non-profit educational institution.

"One of life's quiet excitements is to stand somewhat apart from yourself
 and watch yourself softly become the author of something beautiful."
[Norman Maclean in "A river runs through it."]