Tuesday, February 21, 2006

Metadata Object Description Schema

Some proposed changes in MODS:
We would like to make some minor changes to MODS for a version 3.2. This will be considered an incremental version in that it will not invalidate existing records. We plan to work on more extensive changes in a version 4.0 in the near future.

Proposed changes for MODS v. 3.2
  1. Add an attribute linkInfo to <location><url> to allow for notes associated with the link (MARC 856$z). (For DLF Registry of Digital Masters)

    We first considered adding an element like <urlNote>, but decided on an attribute because this note is associated with the URL. You could have a <physicalLocation> (for the repository that is responsible for the resource) and <url> (for the URL of the resource) that are bound together in a <location> container. So just adding a note under <location> wouldn't tell you whether it belongs with <physicalLocation> or <url>. It is associated with the link given in <url>, so an attribute seemed appropriate.

  2. Add enumerated values under digitalOrigin to accommodate more of those in MARC ER 007/11 (Antecendent/source) (also for DLF Registry of Digital Masters)

    Now the MODS values are:
    born digital
    reformatted digital (which means reformatted to digital from the original)

    We want to add:
    digitized microfilm (MARC code b)
    digitized other analog (MARC code d)

    In the next full version of MODS (4.0) we could change "reformatted digital" to something more precise (to bring out that it means digitized from analog). Since this version should not invalidate existing instances, we would not want to make that change now.

  3. Add ID attribute to part element. This will allow the element to be referred by an IDREF attribute from within the same document. When MODS is used in METS documents, we need to be able to reference MODS relatedItem and part elements using the METS div DMDID attribute (which is an IDREF type). This makes it possible to associate particular entities represented by divs in the structMap with particular descriptive information.

  4. Restore ID attribute to relatedItem element. (It disappeared inadvertently from Version 3.1-- was in 3.0).

  5. Allow part element to be optionally empty (for when the ID and type attribute values contain all the information needed about the part).


    <mods:relatedItem ID="DMD_article01" type="constituent">
    <mods:title>Wien, 10. mai.</mods:title>
    <mods:part ID="DMD_article01_para01" type="paragraph"/>
    <mods:part ID="DMD_article01_para02" type="paragraph"/> </mods:relatedItem>

    The idea is that it is possible to use the part element plus type attribute to note the existence of paragraphs (as suggested in the MODS Outline of Elements and Attributes). Given that the above construct expresses all I needed to express (i.e. the existence of a sequence of paragraphs in document order) it renders the text subelement superfluous. Currently the text child element (or one of the other child
    elements- detail, extent, or date- are required.

    <mods:relatedItem ID="DMD_article01" type="constituent">
    <mods:title>Wien, 10. mai.<mods:title>
    <mods:part ID="DMD_article01_para01" type="paragraph">
    <mods:part ID="DMD_article01_para02" type="paragraph">

  6. Make a few elements global that are referenced in the DCMI Library Application Profile (these are subelements under other elements):

    dateCaptured (under <originInfo)
    edition (under <originInfo>
    physicalLocation (under <location>)

  7. Addition of collection description elements Most of the elements in the DCMI Collection Description Profile map already to MODS. We are thinking we should provide for them all, since in many cases people will be exposing their metadata in OAI as MODS, but there may be collection description information they want along with their items that are exposed as MODS. So the following are the elements that would need to be added:

    Accrual periodicity: defined as "The frequency with which items are added to a collection" MODS has frequency under <originInfo>, although this is uncontrolled text and is under <originInfo> (and used for MARC 310 information). That is used for the frequency of a publication as opposed to the frequency of adding something to a collection. But then if what you are describing is a collection you probably could use this frequency and add an authority for a controlled list of values.

    Accrual method: in MARC holdings this is Method of acquisition (008/07)

    Accrual policy: in MARC holdings similar to Receipt or acquisition status (008/06).

If this will require a lot of discussion I'd rather wait until the next full version of MODS, since we want to get 3.2 out. If people think we should pursue it now because they think it's important to have it right away, I'll suggest some elements.

Comments welcome. We'd like to be able to put out a new schema in a few weeks.

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