[ale] [OT] Help with Significant Figures Explaination

[Ed Cashin]

On Fri, Oct 17, 2008 at 12:58 PM, Jim Kinney <jim.kinney at gmail.com> wrote:
...
> The definition I was taught and still use is the least significant digit
> is 1/2 the smallest MARKED unit on the measuring device. So a meter
> stick marked to the millimeter is good to .5mm. By eye, a reasonable
> person can decide if something is closer to 1mm or 2mm but judging
> beyond that is too imprecise.

I think that's the working definition I learned in high school.
It seems reasonable, practical, and easy to justify.

Do you know of any authoritative source that popularized
this way of thinking about significant digits?  I don't know
whether my teachers cited an authority.  I think they just
presented it as self evident.

-- 
  Ed Cashin <ecashin at noserose.net>