Norvig's Law

by parenthesis • 18 years ago

14 14 18 years ago

cperciva• 18 years ago

Peter Norvig is wrong. He claims that "Any technology that surpasses 50% penetration will never double again (in any number of months)," but the raw foodism reached 100% penetration millions of years ago, fell off sharply after the discovery of fire, and has doubled several times in the past couple of decades.

zandorg• 18 years ago

But isn't it the population that's 100%, not how much food each gets?

aneesh2• 18 years ago

You missed cperciva's point.

Any technology that passes 50% penetration can indeed double again if in the future it goes below 50%.

rocha• 18 years ago

It depends on the unit that is doubling. From how I read the claim, Peter Norvig is using penetration percentage as such unit. Once you reach 50%, doubling means 100%, which is very unlikely since it is almost certain that somewhere in the world there is someone that does not use certain technology (meaning writing, clothing, radio, cellphones or whatever...). In short: the claim is just a clever joke :)

aneesh2• 18 years ago

Yes, we got the joke. But suppose in 50 years we come up with a cool technology that is so good it drives cell phone penetration down to 1% (ie young people growing up then never buy cell phones). Then cell phones can make a comeback and double to 2%. And double again to 4%, etc.

fp• 18 years ago

One could argue, that "raw foodism" isn't really technology. In your example the technology would be "fire" or "cooking".

timtrueman2• 18 years ago

I know a few people that carry two cell phones... It's a technicality but you can have more than 100% market penetration. Does that count?

"Luxembourg racked up 158 mobile subscriptions per 100 people, closely followed by Lithuania (127) and Italy (122)." Source: http://news.bbc.co.uk/1/hi/technology/7116599.stm

etal3• 18 years ago

The article's not that long! Here's the second half:

To be clear, it all depends on what you count. If you're counting units sold, you can double your count by selling everyone 1 unit, then 2, then 4, etc. (In Finland I understand that cell phone usage is above 1 per capita, but still growing.) If you're counting the total number of households that own the product, you can double your count by doubling the population, or by convincing everyone to divorce and become two households. But if you're counting percentage of people (or households), there's just no more doubling after you pass 50%.

timtrueman2• 18 years ago

Right, I actually did read that far. I'm just trying to illustrate unless he defines it in a way the excludes cases like that, I'm not sure you can call it a law...a generalization with exceptions, maybe. As his law is written, the cell phone example kinda disproves it. I think the problem is that paragraph you quoted can't easily be reduced to language that fits in that blue box. Just playing devil's advocate...

bayareaguy• 18 years ago

This law only holds true for very broad catagories of technologies e.g. use of fire, hydraulics, electricity, radio, genetics, atomic power, nanotech, etc.

If you try to apply the it to something more narrow you run into the problem that many specific technologies come in and out of favor depending on market conditions.

malkia• 18 years ago

Any technology that surpasses 33.3333% penetration will never tripple again (in any number of months).

Norvig's Law

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