[e2e] About the primitives and their value

David P. Reed dpreed at reed.com
Thu Aug 10 13:42:52 PDT 2006


Joe Touch wrote:
> If we saw a paradigm that didn't relocate the problem (e.g., as
> publish/subscribe does), sure. I haven't seen one yet. From an
> information theoretic view, I'm not sure it's possible, either, but I'd
> be glad to see suggestions.
>
>   
May I suggest that information theory is not the relevant way to think 
of this?  Information theory is good for lots of things, but it doesn't 
capture intentionality at all.

All you can do with information theory is quantify conditional entropy 
before and after changes that are defined by a channel model that you 
import from some non-information theoretic source.

It's like saying Hoare's formal annotation of sequential programs tells 
you what programs are.  In fact the annotation tells you nothing about 
the programs, all it lets you do is deduce what any particular program 
may do based on the mapping from its syntax to its predicate-calculus 
model.  Hoare's logical formalism doesn't tell you that all programming 
languages must be sequences of statements executed one after another - 
that comes from the programming language designer's choice.

Most *applied* information theory results talk loosely about "sending" 
and "receiving", but in fact the notion of sending and receiving are 
arbitrary elements to which information theory's tools are applied.

In the case of radio, physics tells you what happens in the field 
between antennas.  In a network, the particular hardware connections and 
manufacturing and code does.  All information theory does is give you a 
language to describe and reason about such systems.  It cannot tell you 
what kind of systems you can design or build.



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