More Than Fit For The Future

An EvoDebate Position StatementRobert E. SmithDirectorThe Intelligent Computer Systems CentreThe University of The West of England, Bristolwww.csm.uwe.ac.uk/icsc

Disheartening News:

Empirical Demonstrations that show the region where EC is “best” amongst search algorithms is very narrowCriticisms of Holland’s TheoriesThe No-Free-Lunch TheoremLeaving Us Asking: What is the niche for EC? Is it really that

useful for anything? Have we all been deluded?

My Argument…

Craft and Technology almost always lead scientific understandingBecause of the hard edges of computing, computer scientists aren’t used to this factComplex systems based paradigms (like EC) best lend themselves to craft

An Example

Consider the longitude problem How does one determine one’s

longitude on Earth? This was once the most important

technical (and commercial) problem in the world

Clocks (to determine one’s local time relative to home time) are provably inadequate for this task, since all clocks are always inaccurate

Clearly…

The only solution for this task is an astronomical one, since time of day (and thus longitude) is an astronomical problemIt was once accepted scientific fact that the only adequate solution for the longitude problem was to look up, at the perfect clockwork of the stars

The Real Solution

Harrison identified the problem…

As technological, not scientific or mathematical. He asked:Could one make the inherently flawed clock good enough to solve the problemThe fact that one could do so was a shock to the scientific world, but not to the world of craftsmen

Craft works beyond scientific understanding

We in computing don’t usually face this fact

Another example

Simon Newcomb (another astronomer) offered strong scientific arguments that heavier-than-air flight was impossibleHis chief arguments concerned scale up Weight scales as the cube, lift scales as

the square, therefore, there is a limit to the size of heavier-than-air vehicles.

Newcomb argued that large birds were clearly near this limit

And, of course, he was right

All Real Aircraft, Ever

Log (wing surface area)

Log

(wei

ght)

Heavier-than-air flight has a very narrow space of usefulness

3/2 slope

No Free Lunch? No S*#t.

Wolpert and Macready, 1995 When performance is averaged over

all possible search spaces, all search algorithms perform equally well (including enumeration)

This fact has nearly no practical value, and isn’t a surprise to technologists and engineers at all

So, I say:

Delivering “pretty good” solutions is an important goalConcepts of crisp problems and crisp optimality are illusions that seldom exist in the real worldFilling the pretty-good-solution niche is the appropriate goal for soft computing (particularly EC)

Suggested EC Concentrations

co-evolutionadaptive agentsonline adaptation to changing environments,machine innovation and creativityopening our minds to industrial problems where computer algorithms are yet to be applied, but where pretty-good, pretty-fast solutions have real cash value.