The EAD Schema and the EAD DTD are different expressions of the EAD
"grammar" or "rules". There are some differences between the two which
depend upon the ability of the W3C XML Schema language to permit certain
"rule" expressions DTD's do not. For example, as Michael has previously
pointed out, the schema will check that countrycode attributes values are
uppercase while the DTD does not. In addition to such datatyping, one of
the major advantages of the schema is that it allows EAD instances to be
embedded and validated within other XML documents, particularly METS
documents.
One may use one or the other to validate EAD instances. In general, this
is done with a DOCTYPE declaration to validate against the DTD and
namespace declarations to validate against the schema.
Hope this helps,
Terry
On Wed, 13 Sep 2006, Michael Rush wrote:
> Michelle,
>
> Sorry if my shorthand for "local file path" confused you. There shouldn't be
> a space between file:/ and the path.
> Try the following, I hope it works for you.
>
> xsi:schemaLocation="http://www.archivists.org/BetaSchema20060901
> file:/C:/ead_schema/ead.20060901.xsd"
>
> Regarding the need to delete the doctype declaration, I'm no expert on these
> things, but linking to both a DTD and a schema seems like the same as linking
> to multiple DTDs. It doesn't make sense to reference more than one set of
> rules for the structure of an xml instance. Plus, there are some not
> insignificant differences between DTD valid and Schema valid instances.
>
> Mike
>
> At 10:01 AM 9/13/2006, you wrote:
>> Thanks for the detailed instructions, Michael. Maybe you or someone
>> else can help me out a little further -- I'm using XMetaL 4.5 and can't
>> seem to get it working. Is the word "file: " actually supposed to be in
>> the schemaLocation? The examples I found on the web didn't show it. I
>> put both the .xsd files in the same directory as the document I was
>> attempting to validate and tried all of these:
>>
>> xsi:schemaLocation=" http://www.archivists.org/BetaSchema20060901
>> file:/ ead.20060901.xsd"
>> xsi:schemaLocation=" http://www.archivists.org/BetaSchema20060901 file:
>> ead.20060901.xsd"
>> xsi:schemaLocation=" http://www.archivists.org/BetaSchema20060901
>> ead.20060901.xsd"
>> xsi:schemaLocation=" http://www.archivists.org/BetaSchema20060901
>> C:\ead_schema\ead.20060901.xsd"
>> xsi:schemaLocation=" http://www.archivists.org/BetaSchema20060901
>> C:/ead_schema/ead.20060901.xsd"
>>
>> Nothing works, I keep getting the error message, "The document could
>> not be opened because an XML Schema was not specified." XMetaL does let
>> me browse for a schema if it can't find one, so I tried that next. If I
>> browse for a schema and specifically select the ead.20060901.xsd schema,
>> I then get an error that the element ead is "not permitted by the
>> document's DTD." Any idea what I'm doing wrong?
>>
>> I'm puzzled as to why one has to delete the doctype declaration. I
>> presume it's because the dtd doesn't support the xmlns attributes for
>> the EAD element? But if not, why not? Shouldn't the DTD and the schema
>> work together? Having to manually edit a file to switch between the DTD
>> and the schema seems awkward...or is the presumption that if you have a
>> good schema you don't need to validate against the DTD so you just don't
>> use the DTD anymore?
>>
>> Forgive me if these are dumb questions, I know very little about
>> schemas and have not worked with them at all. Thanks!
>>
>> Michele
>
> ____________________________________
> Michael Rush | [log in to unmask]
> Processing Archivist / EAD Coordinator
> Beinecke Rare Book & Manuscript Library
> Yale University
> P.O. Box 208240
> New Haven, CT 06520-8240
> Tel: (203) 432-8123 Fax: (203) 432-4047
Terry Catapano
Special Collections Analyst/Librarian
Columbia University Libraries Digital Program
212-854-9942
[log in to unmask]
|