span and interval

[igm...@gmail.com]

Hi
I have a basic question about the meaning of span and interval in a phase:
Data:
Span 0-92 years 95.4%
Interval 0-397 years 95.4%

I have three dates of the same phase, Span: is this means that there are a period of time of 0-92 years between each date (1st C14 /0-92years/ 2nd c14 /0-92years/ 3rd c14) of the phase?, and Interval: is this means that all the phase has a duration between 0 and 397 years?

Thank you very much

[MILLARD A.R.]

> From: igm...@gmail.com
> Sent: 28 March 2014 17:55

>
> I have a basic question about the meaning of span and interval in a
> phase:
> Data:
> Span 0-92 years 95.4%
> Interval 0-397 years 95.4%
>
> I have three dates of the same phase

Span gives you the difference between the first and last radiocarbon dates within the phase, and only considers the samples you have dated. If you have set boundaries either side of your phase then Interval gives you the time difference between the boundaries, and considers the dated samples to be just a sample of the possible duration of the phase. With only three dates the Interval will be much more uncertain than the span.

Best wishes

Andrew
--
 Dr. Andrew Millard 
e: A.R.M...@durham.ac.uk | t: +44 191 334 1147
 w: http://www.dur.ac.uk/archaeology/staff/?id=160
 Senior Lecturer in Archaeology, Durham University, UK