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From: jbn@glacier.STANFORD.EDU (John B. Nagle)
Newsgroups: comp.cog-eng
Subject: Re: Technological overcomplexity in 1523
Keywords: cognitive engineering, design, comnplexity, history of technology
Message-ID: <17596@glacier.STANFORD.EDU>
Date: 1 Aug 88 00:09:24 GMT
References: <585@sdics.ucsd.EDU>
Reply-To: jbn@glacier.UUCP (John B. Nagle)
Distribution: all
Organization: Stanford University
Lines: 35

In article <585@sdics.ucsd.EDU> norman@sdics.UUCP (Donald A. Norman - 
danorman@ucsd.edu (or .bitnet)) writes about the overcomplexity of plows.
But the complexity of the problem is very real.  The difference between
a good plow and a bad one, in terms of the amount of plowing one can
do in a day with the same amount of pulling power, is huge.  Thomas
Jefferson, who, after all, made his money running a farm, worked, and published,
on the proper curves for plow blades.  The problem is comparable to propellor
design, which makes sense when you think about it.

There are interrelationships between plow design and whether a farmer should
use horses or oxen.  Horses eat more, but go faster.  On the other hand,
horses need more complex harness; a yoke will work, but the horse cuts off
his own wind when he really pulls, and a horse in a yoke does less useful
work than an ox.  It took people several thousand years to figure out
the solution to that problem.  In fact, draft horse harness wasn't perfected
until the 1930s, and only as part of a last-ditch effort to compete with
tractors.  The problems of hitching up multiple animals so that all of
them share the load equally, none of them can goof off, one man can drive
a large team, the turning radius is small enough to be useful in 
farming, the horses don't interfere with each other's movements, and
the harness can be put on in a reasonable time, are quite complicated.  See 
"The Draft Horse Primer" for details on this esoteric subject.

So the problem is inherently complicated.  The easy solution is available
today; just get a big tractor and bull your way through.  With good steels,
good plow designs, and a big engine, the technology becomes "user friendly",
because the tough design problems were solved back at the farm-equipment
factory.  

We see an exact analogy in computing.  It takes a lot of CPU power to make
a system user-friendly.  Systems such as the Macintosh use most of their
CPU power operating the user interface.  This only became feasible when
CPU power became cheap enough that it could be used as a big hammer to
hide the internal complexities of the system.

					John Nagle