[ale] [OT] Help with Significant Figures Explaination

[tfreeman at intel.digichem.net (tom)]

I have seen something resembling a justification _once_ before this
recent search. On this last search I found some hand waving from
statistics, but given the level of numeric sophistication, I
should consider something a little less sophisticated.

On Fri, 17 Oct 2008, Ed Cashin wrote:

> 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.
>
>