>> In the same way as nobody mixes up a thousand and a million.
>
> Echoes my thoughts exactly; a thousand-fold difference "mentally"
> matters much more for smaller numbers.

I read a book recently which suggests that the human sense of numbers is 
inherently logarithmic, and that humans instinctively use ratios to 
assess things. Because, think about it, if you're going to climb tree A 
or tree B, it doesn't actually matter precisely how many applies are in 
each tree. What matters is what the /ratio/ between them is.

...which would explain why, for really large numbers, people develop 
this strange sense of numbness, as if all really big numbers are somehow 
"equally huge". (A similar thing happens with really tiny numbers, by 
the way.)

> It's also a bit rare that I see either
> of these errors, so I don't know where Invisible got the "to most
> people" aspect, although surveys testing the general public's math
> knowledge tend to be scary enough that I suppose it's possible.

The guy who does XKCD clearly sees this too. Maybe you only meet smart 
people? Because where I live, there are many, many dumb people.

> One error I *do* see all the time though, is a misuse of the term
> "exponential" to mean anything superlinear (or just "a lot").

This.

Did you know that an exponential curve actually starts out /quite 
shallow/? Saying that something is increasing "exponentially" does /not/ 
just mean it's increasing quite quickly. It means a very specific 
mathematical relationship.

Post a reply to this message