[DDI-SRG] request for assistance

[Wendy Thomas]

Sanda,

I think it might be cleaner to send them to me and I'll send on any that 
need more info. I'll certainly be collecting questions and answers from 
you and others, but unless the guys want to see them direct then this 
might be a cleaner way to do it. I've put in some answers below.


On Fri, 13 Jul 2007, Sanda Ionescu wrote:

> Hi, Wendy.
>
> I'm beginning to look "in earnest" at the candidate draft and I have
> questions...
> I anticipate needing lots of clarifications as I attempt to update my
> old examples and create the new one.
> So please bear with me!
> I expect you are willing to answer, as you have always been, and one
> question would be - do I send my questions only to you, or do I send to
> the entire SRG?
>
> And here comes the first batch (as I'm looking at Identification):
> 1. Can objects be referenced even if they sit "outside" maintainable
> objects? (It was my understanding that only maintainables can stand
> alone, all others need to be within a maintainable?)
Since all the major modules and instance are maintainable everything sits 
within at least one maintainable object. Objects can be referenced as long 
as they have an ID. Then can be inside or outside the maintainable object 
you are referencing from.


> 2. name of maintainable object (in the URN) - is this actually the name
> of the ddi tag?

If the reference is in a different maintainable object you work your way 
down the tree. So if you have a maintained CategoryScheme with the ID of 
CATSCHEME_1 and you want to reference the category within it of CAT_X you 
would have the following info:

ddi:3_0:[object class of maintained object]:[Agency ID]:[ID of maintained 
object]:[version]:[object class of referenced object]:[ID of referenced 
object]:[version]

ddi:3_0:CategoryScheme:icpsr.umich.edu:CATSCHEME_1:1_0:Category:CAT_X:1_0

I see that the info in Part I pg 32 is odd. I'll put in a bug fix on that.


> 3. maintenance agency (in the URN) - is this information copied from the
> Identifying Agency tag ?, and

YES


> 3b. if the above needs to be in the form of a URL, it means the ddi tag
> needs to contain a URL, no? should it not have a URL type rather than
> NCNAME?

I think NCName is correct as there are no breaks and it starts with a 
letter, but put it in as a bug after Pascal gets you on the bug tracker 
and we'll make sure this is verified. It may be a leftover from when we 
were going to have a registry and identifiers like ICPSR or MPC.

> 4. If the version of an identifiable element is always inherited from
> above, why does it need to be stated in the URN? (see your example in
> the manual - a variable is not versionable, so then why do we need its
> version in the URN)

If it is an IdentifiableID then you don't need it as you are correct it 
inherits. If you are referencing a VersionableID you need to include the 
version


> 5. It is my understanding that all of the versioning tags need to be
> filled in for maintainables, or else we would not be able to build URNs?
> and...
The only one you can dispense with is the Version Number as the default is 
1.0 (expressed as 1_0 in the URN) It must be included in the URN


> 6. If a maintainable lives within a maintainable (i.e. variable scheme
> within study unit) will it inherit the versioning info from the
> maintainable above (if not specified), or does this need to be specified
> for each and every maintainable?

The assumption is that it inherits from the parent. If you don't put the 
information in and you then pull the pieces apart and maintain them 
separately you will need to make the inherited information explicit at 
that point.

Let me know if any of this was unclear.

>
> Thanks Wendy,
> I really appreciate your help.
> Sanda.
>
>
> Sanda Ionescu
> ICPSR
> University of Michigan
> P.O. Box 1248
> Ann Arbor, MI 48106
>
> Phone, Fax: 734-615-7890
>
>
>

Wendy L. Thomas                          Phone: +1 612.624.4389
Data Access Core Director		 Fax:   +1 612.626.8375
Minnesota Population Center              Email: wlt at pop.umn.edu
University of Minnesota
50 Willey Hall
225 19th Avenue South
Minneapolis, MN 55455