6 ms·

Isn't it odd and curious and such like that the chunks of time bandied about are units of ten? Coincidentally equal to the number of fingers on our hands. 10 ye

Isn't it odd and curious and such like that the chunks of time bandied about are units of ten? Coincidentally equal to the number of fingers on our hands. 10 years. 10,000 hours. I'd be willing to bet my granny's dentures that if we had eight fingers on each hand those numbers would be 16 years and 65536 hours (well, I mean it would still be 10 and 10,000 but you know what I mean). Also, did you know that in many cultures (ancient Greece, Aramaic, Hebrew, Chinese, to name but some) 10,000† just means "a heck of a lot", "more than you can count". So you see, 10,000 is a bit too magical for me to take seriously. † Here's a wikipedia entry but I think I read about this in a history of mathematics book, cannot remember which one, sorry. http://en.wikipedia.org/wiki/10000_(number) http://en.wikipedia.org/wiki/10000_(number)

gehar 14y ago
Why is that a reason to not take it serious? It's an order-of-magnitude estimate, like Carl Sagan's "billions and billions" of stars, or the Bible's "40"
jotux 14y ago
After reading Outliers I think of 10000 hours as approximately five years of full-time work, which is a much easier quantity to think about.
- davidp 14y ago
  Such a rule-of-thumb needs a crucial caveat (said by others better than I'll say it here): You need N years of steadily, deliberately advancing full-time work. There's a fundamental difference between gaining 10 years of experience, and gaining 1 year of experience 10 times. It's harder than one might think to sustain continual real advancement over such a period; generally the employer paying the bills needs us to occasionally "take one for the team" and do scut-work for a while, simply due to normal business unpredictability; or the work dries up completely and you have a hiccup while you start somewhere new. A source of work where opportunity continuously keeps up with ability is a precious thing.
  - nostrademons 14y ago
    The other caveat is that you have to be concentrating and paying attention to your performance for those 10,000 hours. Very few people, if any, have the metacognition and executive function abilities to pay attention and steadily improve for 8 hours a day. The experts in Outliers and the research it's based upon would typically practice for only 4-5 hours/day and then rest, or do fun stuff like playing through pieces or doing a few flips or easy jumps. A bunch of anecdotal evidence from myself and my friends in Ph.D programs or professional jobs, plus RescueTime's survey of YC founders, also supports that most people can get no more than 4-5 hours of cognitively demanding work in per day. Hence the 10 years = 10,000 hours. When you're working an 8 hour day, it's usually more like 4-5 hours a day of heavy concentration, plus 3-4 of overhead (checking e-mail, responding to e-mail, doing grunt work like unit tests that you already know how to do, talking to coworkers, sitting in meetings). If you're lucky. For many senior devs it's 8 hours of talking to people and zero coding. (Although you can turn that into deliberate practice as well. For a while, shortly before and after I made Senior SWE at Google, I was spending the vast majority of my time answering questions from my peers and doing code reviews. I had very little time for coding and my basic coding skills improved very little, but I got really good at being able to dive into an unfamiliar codebase, identify what people were trying to accomplish, and find a way to make it happen in a not-completely-gross fashion. That skill proved invaluable later on, and basically saved the launch of one high-profile Google product.)
adamtj 14y ago
Imprecision (one significant digit) + Benford's law (most numbers start with 1) means most numbers needing citation are of the form 10^n. http://en.wikipedia.org/wiki/Benfords_law http://en.wikipedia.org/wiki/Benfords_law Interestingly, this would be true even if we had 8 fingers per hand. If we had 16 total fingers, 16 (base 10) would be written as "10" (base 16). 15 (base 10) would be a one digit number in base 16. On the other hand, you'd rather have six fingers. Base 12 would be great because it has whole thirds! Also 12 is divisible by four numbers (2, 3, 4, and 6). 10 is divisible only by only 2 and 5, and fifths are much less common than thirds. That's why 12 inches in a foot and 3 feet in a yard is a nice way to measure things (though the rest of the imperial system, excepting maybe Fahrenheit, has no excuse!)
- danbruc 14y ago
  That's why many things in the metric system are designed on a grid with edge length 60 - it gives you many possibilities for subdivisions. For example the dimensions of most furniture is based on this - 30 cm, 45 cm, 60 cm, 90 cm, 120 cm and 240 cm everywhere.
  - dredmorbius 14y ago
    Not that furniture might not, say, be scaled to fit human proportions or anything funky like that.
    - trevor-rollin 14y ago
      Yup, most desks and tables are around 75cm high because they're, well, designed for humans, not mathematical convenience.
- triplesec 14y ago
  ... and this is why we had Pounds, Shillings and Pence (£./.d) in the UK until 1971. http://en.wikipedia.org/wiki/Decimal_Day http://en.wikipedia.org/wiki/Decimal_Day Much more mathematically interesting, and tortured schoolchildren for many years, to their great benefit. Twelve pennies in a shilling, and 20 shillings to the pound sterling. Coins were at or soon before decimalisation: Farthing (1/4d), ha'penny (1/2d), penny, threppence (3d), sixpence or tanner (6d), shilling, florin (2/), half crown (2/6), and the crown (5/). The first paper note was the ten-bob note (10/), tequivalent to 50 new pence, followed by the Pound (20/). Until 137 there had been sovereign and half-sovereign coins instead of the 10/ and pound notes.
yen223 14y ago
> Also, did you know that in many cultures (ancient Greece, Aramaic, Hebrew, Chinese, to name but some) 10,000† just means "a heck of a lot", "more than you can count". So you see, 10,000 is a bit too magical for me to take seriously. That's the salient point. When Norvig says it takes "10 years" to be a programmer, he means it takes a heckuva long time to master the art, not that it takes 87648 hours with a 95% confidence interval. That figure is not meant to be taken at face value.

gehar 14y ago

Why is that a reason to not take it serious? It's an order-of-magnitude estimate, like Carl Sagan's "billions and billions" of stars, or the Bible's "40"

jotux 14y ago

After reading Outliers I think of 10000 hours as approximately five years of full-time work, which is a much easier quantity to think about.

davidp 14y ago
Such a rule-of-thumb needs a crucial caveat (said by others better than I'll say it here): You need N years of steadily, deliberately advancing full-time work. There's a fundamental difference between gaining 10 years of experience, and gaining 1 year of experience 10 times. It's harder than one might think to sustain continual real advancement over such a period; generally the employer paying the bills needs us to occasionally "take one for the team" and do scut-work for a while, simply due to normal business unpredictability; or the work dries up completely and you have a hiccup while you start somewhere new. A source of work where opportunity continuously keeps up with ability is a precious thing.
- nostrademons 14y ago
  The other caveat is that you have to be concentrating and paying attention to your performance for those 10,000 hours. Very few people, if any, have the metacognition and executive function abilities to pay attention and steadily improve for 8 hours a day. The experts in Outliers and the research it's based upon would typically practice for only 4-5 hours/day and then rest, or do fun stuff like playing through pieces or doing a few flips or easy jumps. A bunch of anecdotal evidence from myself and my friends in Ph.D programs or professional jobs, plus RescueTime's survey of YC founders, also supports that most people can get no more than 4-5 hours of cognitively demanding work in per day. Hence the 10 years = 10,000 hours. When you're working an 8 hour day, it's usually more like 4-5 hours a day of heavy concentration, plus 3-4 of overhead (checking e-mail, responding to e-mail, doing grunt work like unit tests that you already know how to do, talking to coworkers, sitting in meetings). If you're lucky. For many senior devs it's 8 hours of talking to people and zero coding. (Although you can turn that into deliberate practice as well. For a while, shortly before and after I made Senior SWE at Google, I was spending the vast majority of my time answering questions from my peers and doing code reviews. I had very little time for coding and my basic coding skills improved very little, but I got really good at being able to dive into an unfamiliar codebase, identify what people were trying to accomplish, and find a way to make it happen in a not-completely-gross fashion. That skill proved invaluable later on, and basically saved the launch of one high-profile Google product.)

adamtj 14y ago

Imprecision (one significant digit) + Benford's law (most numbers start with 1) means most numbers needing citation are of the form 10^n. http://en.wikipedia.org/wiki/Benfords_law http://en.wikipedia.org/wiki/Benfords_law Interestingly, this would be true even if we had 8 fingers per hand. If we had 16 total fingers, 16 (base 10) would be written as "10" (base 16). 15 (base 10) would be a one digit number in base 16. On the other hand, you'd rather have six fingers. Base 12 would be great because it has whole thirds! Also 12 is divisible by four numbers (2, 3, 4, and 6). 10 is divisible only by only 2 and 5, and fifths are much less common than thirds. That's why 12 inches in a foot and 3 feet in a yard is a nice way to measure things (though the rest of the imperial system, excepting maybe Fahrenheit, has no excuse!)

danbruc 14y ago
That's why many things in the metric system are designed on a grid with edge length 60 - it gives you many possibilities for subdivisions. For example the dimensions of most furniture is based on this - 30 cm, 45 cm, 60 cm, 90 cm, 120 cm and 240 cm everywhere.
- dredmorbius 14y ago
  Not that furniture might not, say, be scaled to fit human proportions or anything funky like that.
  - trevor-rollin 14y ago
    Yup, most desks and tables are around 75cm high because they're, well, designed for humans, not mathematical convenience.
triplesec 14y ago
... and this is why we had Pounds, Shillings and Pence (£./.d) in the UK until 1971. http://en.wikipedia.org/wiki/Decimal_Day http://en.wikipedia.org/wiki/Decimal_Day Much more mathematically interesting, and tortured schoolchildren for many years, to their great benefit. Twelve pennies in a shilling, and 20 shillings to the pound sterling. Coins were at or soon before decimalisation: Farthing (1/4d), ha'penny (1/2d), penny, threppence (3d), sixpence or tanner (6d), shilling, florin (2/), half crown (2/6), and the crown (5/). The first paper note was the ten-bob note (10/), tequivalent to 50 new pence, followed by the Pound (20/). Until 137 there had been sovereign and half-sovereign coins instead of the 10/ and pound notes.

yen223 14y ago

> Also, did you know that in many cultures (ancient Greece, Aramaic, Hebrew, Chinese, to name but some) 10,000† just means "a heck of a lot", "more than you can count". So you see, 10,000 is a bit too magical for me to take seriously. That's the salient point. When Norvig says it takes "10 years" to be a programmer, he means it takes a heckuva long time to master the art, not that it takes 87648 hours with a 95% confidence interval. That figure is not meant to be taken at face value.