Mariela Hristova's Assignment 3

 

Markup and metadata contribute to the functions of digital libraries not just as distinct elements but through their powerful interaction with one another.

Individually, markup allows us to specify in a machine-readable manner the structure of documents and how they should be presented, while metadata allows us to add different types of information about the digital document (i.e. descriptive, administrative, etc.). Thus, markup adds structure and metadata adds content. We can easily see that working together those two elements can contribute some of the main value-added functions of digital libraries: easy navigation and access to the collection.

To make markup and metadata work seamlessly together, we need a way of customizing their interaction without diminishing computers' ability to interpret that interaction. Naturally, standards come into play to maintain interoperability. Our use of markup depends on following standards for syntax, such as DTDs for HTML documents. Our use of metadata relies on standards for what content to add to a document, such as MARC or Dublin Core. Customization, however, would be very hard to achieve, if we just had separate standards for markup and for metadata and no flexible way to design their interaction. Luckily, we have XML.

XML provides a constructive way of putting markup and metadata together by extending the use of markup to structure not only documents, but the metadata about them as well. Moreover, we are afforded this freedom not through a huge, complex and all-encompassing standard, but through a set of principles on how to define our own custom-made standard, i.e. our DTD for the XML documents in the digital library. So, we can continue to use current metadata standards and maintain the relation of our metadata to the relevant documents by applying a unified markup to both the documents and the metadata; thus, tightening the association between a document and its metadata and achieving data integrity for our digital collection.

Below is an example how XML can bring markup and metadata together to create a self-descriptive entity. I have chosen to create an XML document that will be relevant to my group's digital collection, so my example is applying Dublin Core metadata to an album.

View the real XML file or follow the representation below.

<?xml version="1.0" encoding="ISO8859-1" ?>
  <!DOCTYPE album [
    <!ELEMENT album (song)>
    <!ELEMENT song (title,creator,subject,description,publisher,
                    contributor,date,type,format,identifier,
                    source,language,relation,coverage,rights)>
    <!ELEMENT title (#PCDATA)>
    <!ELEMENT creator (#PCDATA)>
    <!ELEMENT subject (#PCDATA)>
    <!ELEMENT description (#PCDATA)>
    <!ELEMENT publisher (#PCDATA)>
    <!ELEMENT contributor (#PCDATA)>
    <!ELEMENT date (#PCDATA)>
    <!ELEMENT type (#PCDATA)>
    <!ELEMENT format (#PCDATA)>
    <!ELEMENT identifier (#PCDATA)>
    <!ELEMENT source (#PCDATA)>
    <!ELEMENT language (#PCDATA)>
    <!ELEMENT relation (#PCDATA)>
    <!ELEMENT coverage (#PCDATA)>
    <!ELEMENT rights (#PCDATA)>
  ]>

<ALBUM>
   <SONG>
      <TITLE>The value listed here</TITLE>
      <CREATOR>The value listed here</CREATOR>
      <SUBJECT>The value listed here</SUBJECT>
      <DESCRIPTION>The value listed here</DESCRIPTION>
      <PUBLISHER>The value listed here</PUBLISHER>
      <CONTRIBUTOR>The value listed here</CONTRIBUTOR>
      <DATE>The value listed here</DATE>
      <TYPE>The value listed here</TYPE>
      <FORMAT>The value listed here</FORMAT>
      <IDENTIFIER>The value listed here</IDENTIFIER>
      <SOURCE>The value listed here</SOURCE>
      <LANGUAGE>The value listed here</LANGUAGE>
      <RELATION>The value listed here</RELATION>
      <COVERAGE>The value listed here</COVERAGE>
      <RIGHTS>The value listed here</RIGHTS>
   </SONG>
   <SONG>
      <TITLE>The value listed here</TITLE>
      <CREATOR>The value listed here</CREATOR>
      <SUBJECT>The value listed here</SUBJECT>
      <DESCRIPTION>The value listed here</DESCRIPTION>
      <PUBLISHER>The value listed here</PUBLISHER>
      <CONTRIBUTOR>The value listed here</CONTRIBUTOR>
      <DATE>The value listed here</DATE>
      <TYPE>The value listed here</TYPE>
      <FORMAT>The value listed here</FORMAT>
      <IDENTIFIER>The value listed here</IDENTIFIER>
      <SOURCE>The value listed here</SOURCE>
      <LANGUAGE>The value listed here</LANGUAGE>
      <RELATION>The value listed here</RELATION>
      <COVERAGE>The value listed here</COVERAGE>
      <RIGHTS>The value listed here</RIGHTS>
   </SONG>
</ALBUM>