[plt-scheme] Perplexed Programmers

From: Matthias Felleisen (matthias at ccs.neu.edu)
Date: Wed Aug 29 08:51:59 EDT 2007

In general, you sound like a converted software engineer :-)

Like you, however, I have challenged Tony Hoare in public to
give me numbers of failures before he pushes his software
verification agenda one more time with a silly invited talk.
He was stunned hearing this challenge coming from me but
not one of the 60 attendees at the Federated Logic had a
good response and two voiced their support for my challenge

In practice, I think you underestimate #1 though my analysis
is more subtle:

On Aug 28, 2007, at 11:22 PM, Shriram Krishnamurthi wrote:

> I'll tell you what I think the "software crisis" is.  It's that the
> difficult stuff is possible but virtually none of the easy stuff is
> easy.

That's #1. And it is professionals like us who have failed to
bring across to the general public and to managers that
programming is not an 'idiot' job (though 'idiots' can write
things like programs for their own amusement and that nobody
else uses).

#2 is that we have failures at an order of magnitude that
-- due to software's flexible nature -- can be made to look
like sufficiently partial successes that everyone accepts.
The LA ISD is a prime example. When have you heard of a
bridge worth $95M that has five working lanes and one
broke thru and dropped a few people?

#3 is that we rely almost all the time on the continuity
and error-tolerant nature of the real world to make up
for software production flaws. In the LA ISD story, we
have teachers who use their credit cards to survive.

#4 is the unbelievably low productivity of the average
software engineer. I am comparing this to:
  -- hardware engineers (when they produce hardware)
  -- mechanical engineers who use cars
  -- civil engineers who work on infrastructure
(These are people I have had regular contact with in
the last six years.)

> I think there are two things we're failing at.

I think your specific criticisms are way down the list.

Also in general, I think you have put up a strawman
though I appreciate its function.

> The real tragedy of the past 20 years is not that the Lisp Machine
> didn't grow by two orders of magnitude (cue obligatory joke about
> global warming) but that the Programmer's Apprentice didn't.

If you replace the last "didn't" with "did" on this list
then I like your statement and it expresses a good sentiment
on this list.

-- Matthias

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