To add a couple thoughts to our general discussion of "how good philosophy leads to good engineering", I thought I would send along a couple of graphic snips from the British engineer W. Ross Ashby's "Design for a Brain".
These ideas have been bedrock for me. Ashby clearly describes this same issue that has come up several times -- that the variables describing any "system" are selected by the observer. He punches straight through to the core when he talks about "readings on dials".
"A system is a collection of variables". That is what an algebraic analyst wants to hear. Now, let's explain why it is true for database modeling...
See http://originresearch.com/docs/DesignForABrain.pdf for the complete text.
Bruce Schuman
NETWORK NATION: http://networknation.net
SHARED PURPOSE: http://sharedpurpose.net
INTERSPIRIT: http://interspirit.net
(805) 966-9515, PO Box 23346, Santa Barbara CA 93101
-----Original Message-----
From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx [mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of John F Sowa
Sent: Friday, April 18, 2014 9:34 AM
To: '[ontolog-forum] '
Subject: [ontolog-forum] Formal or functional specifications
I sent the following reply to a discussion on the ontology summit list, but the issues are critical for any ontology.
-------- Original Message --------
Subject: Shareable versus reusable, or shared and reusable
Overly precise specifications can block interoperability and reuse in engineering, medicine, and other fields. Engineers complain that computerized tools can make functional replacements more difficult.
They can also be a deterrent to innovation.
For many purposes, a simple list can be hard to improve:
Toast, muffin, croissant, or daily special
As another example, the shift away from incandescent light bulbs has drawn attention to functional requirements that nobody imagined.
Reducing heat is good. But LED traffic lights don't generate enough heat in winter to melt snow and ice. An incandescent bulb gets hot, but it tolerates heat in an enclosed space. The number of unexpected consequences -- both good and bad -- is open-ended.
Sometimes, the exact spec is critical, and a repair that seems to be a functional replacement can create a disaster. But patients have died because a physician did not know that another option was possible.
For humorous examples, google "redneck repairs". But the questions are serious: Is form or function more important? How much precision is appropriate? What tradeoffs are possible, desirable, or dangerous?
John
