LISTSERV mailing list manager LISTSERV 16.0

Help for DATETIME Archives


DATETIME Archives

DATETIME Archives


DATETIME@C4VLPLISTSERV01.LOC.GOV


View:

Message:

[

First

|

Previous

|

Next

|

Last

]

By Topic:

[

First

|

Previous

|

Next

|

Last

]

By Author:

[

First

|

Previous

|

Next

|

Last

]

Font:

Proportional Font

LISTSERV Archives

LISTSERV Archives

DATETIME Home

DATETIME Home

DATETIME  July 2011

DATETIME July 2011

Subject:

Re: interval precision

From:

"Edward C. Zimmermann" <[log in to unmask]>

Reply-To:

Discussion of the Developing Date/Time Standards <[log in to unmask]>

Date:

Mon, 25 Jul 2011 12:23:50 +0200

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (83 lines)

On Sun, 24 Jul 2011 22:56:29 +0200, [UTF-8?]SaaÅ¡ha Metsärantala wrote
> Hello!
> 
> > think about increasingly precise balances...
> These questions are really interesting! There is no doubt about that! They 
> may also probably be useful.
> 
> If there are use cases, I would really like to include such precision 

Use cases, I think, are a plenty. I think I have over the course of this 
list presented quite a few....

> descriptions within the EDTF specification! No doubt about that!
> 
> My point with this e-mail is the following:
> 
> There is no way to express subtle semantics within a syntax which is too 
> narrow for it. To express such semantic subtleties unambiguously, we need

But I think the semantics have long been implicitly expressed. Its our job 
perhaps to lay them explicitly down in the text for our emerging "standard".

When I ask someone, for example, how much did the object weigh and they 
respond "1 gram" what are they saying? They are implicitly saying that the 
speciment with a precision of 1 gram--- perhaps, at best, 1/2 gram--- weighs 
1 gram. When someone reports "1.200g" they are reporting that with a 
precision of mg a sample tips the balance at "1200 mg". The 
expression "1.2g" is not the same. Its expressing a measure with the 
precision of decagram. While a 1200 mg sample weighs 12 decagrams, a 12 
decagram sample might not weight 1200 mg to a precision of mg.
In weights and measures we typically have zeros (0) left of the decimal 
point beyond the last place to express higher precision. A number such 
as "1.000000" is expressing something beyong the number "1". The problem is 
with 10s left of the decimal point. How can one distinguish 
between "100" with a precision of 1, "100" with a precision of 10 or "100" 
with a precision of 100?

The same "problem" exists with date expressions. We have well defined 
expressions of year, month, day, hour, minute, second,.. perhaps even 
century precision.. but not decade, whence the generalized "x" syntax.

The "stuff" is all there.. sure we could extend things to allow for a more 
general means to express precision.. while I can see a few use cases I 
do not think that they are needed just yet.. and would carry the danger of 
complicating things.. expecially given the lack of widespread "precision 
consciousness" at this time. Many people, I think, that we are addressing 
with the standard don't have a background in natural sciences so some of 
these basic concepts might, at first, seem stange. Its one step at a time!

What we are still missing then in the standard, I think, are:
- clear expression of what has been implicit:
  o that "1994" has year precision, "1994-06" month precision etc..
    A number of examples, I think, would be good.. down to highly precise
    expressions such as !994-05-12T12:22.33Z" (decimal seconds following the
    model I expressed for weights with the limitation to the Caesium 
standard for time)
  o the consequences of precision.
- how to compare things expressed in different precisions.

> a wider syntax helping people storing EDTF information to be aware of the 
> (implied) semantics of the information they store. Other wise, there is a 
> risk that some (many) people will store information containing implied 
> "precision semantics" they are not aware of and some (many) people will 
> read this information with an understanding of the implied "precision 
> semantics" different from that of the person who stored this information.

We don't meed a wider syntax.. only to be more explicit and demanding in our 
standard's text :-)


> 
> Regards!
> 
> [UTF-8?]Saašha,


--

Edward C. Zimmermann, NONMONOTONIC LAB
Basis Systeme netzwerk, Munich Ges. des buergerl. Rechts
http://www.nonmonotonic.net
Umsatz-St-ID: DE130492967

Top of Message | Previous Page | Permalink

Advanced Options


Options

Log In

Log In

Get Password

Get Password


Search Archives

Search Archives


Subscribe or Unsubscribe

Subscribe or Unsubscribe


Archives

August 2019
February 2019
December 2018
November 2018
October 2018
January 2018
August 2017
July 2017
June 2017
April 2017
March 2017
February 2017
August 2016
July 2016
May 2016
April 2016
March 2016
February 2016
January 2016
December 2015
November 2015
October 2015
August 2015
July 2015
June 2015
May 2015
April 2015
March 2015
December 2014
November 2014
March 2014
September 2013
May 2013
February 2013
October 2012
September 2012
August 2012
May 2012
March 2012
December 2011
November 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
February 2010
January 2010
December 2009
November 2009

ATOM RSS1 RSS2



LISTSERV.LOC.GOV

CataList Email List Search Powered by the LISTSERV Email List Manager