Wednesday, February 15, 2006

On wild predictions of human-level AI

Is it just me or has anyone else noticed a spate of predictions of human-equivalent or even super-human artificial intelligence (AI) in recent weeks?

For instance the article futurology facts (now there's an oxymoron if ever there was one) on the BBC world home page quoted the British Telecom 'technology timeline' including:

2020: artificial intelligence elected to parliament
2040: robots become mentally and physically superior to humans

A BT futurologist is clearly having a joke at the expense of members of parliament. Robots won't exceed humans intellectually until 2040 but it's presumably ok for a sub-human machine intelligence to be 'elected' to parliament in 2020. Hmmm.

Setting aside the patent absurdity of the 2020 prediction, let's consider the 2040 robots becoming intellectually superior to humans thing.

First let me declare that I think machine intelligence equivalent or superior to human intelligence is possible (I won't go into why I think it's possible here - leave that to a future blog). However, I think the idea that this will be achieved within 35 years or so is wildly optimistic. The movie i,Robot is set in 2035; my own view is that this level of robot intelligence is unlikely until at least 2135.

So why such optimistic predictions (apart perhaps from wishful thinking)? Part of the problem I think is a common assumption that human level machine intelligence just needs an equivalent level of computational power to the human brain, and then you've cracked it. And since, as everyone knows, computers keep doubling in power roughly every two years (thanks to that nice man Gordon Moore), it doesn't take much effort to figure out that we will have computers with an equivalent level of computational power to the human brain in the near future.

That assumption is fallacious for all sorts of reasons, but I'll focus on just one.

It is this. Just having an abundance of computational power is not enough to give you human level artificial intelligence. Imagine a would-be medieval cathedral builder with a stockpile of the finest Italian marble, sturdy oak timbers, dedicated artisans and so on. Having the material and human resources to hand clearly does not make him into a cathedral builder - he also needs the design.

The problem is that we don't have the design for human-equivalent AI. Not even close. In my view we have only just started to scratch the surface of this most challenging of problems. Of course there are plenty of very smart people working on the problem, and from lots of different angles. The cognitive neuroscientists are by-and-large taking a top-down approach by studying real brains; the computer scientists build first-principles computational models of intelligence, and the roboticists take a bottom-up approach by building at-first simple robots with simple brains. But it's an immensly hard problem because human brains (and bodies) are immensly complex.

Surely the really interesting question is not when we will have that design, but how. In other words will it be by painstaking incremental development, or by a single monumental breakthrough. Will there (need to) be an Einstein of artificial intelligence? If the former then we will surely have to wait a lot longer than 34 years. If the latter then it could be tomorrow.

Perhaps a genius kid somewhere has already figured it out. Now there's a thought.

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