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changes.mady.by.user Bram Luyten (Atmire)

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  1. Not a replacement for text metadata value.Metadata fields still have text values.
    • The text value of a metadata field does not have to be derived from the authority, even if authority control is required for that field.
  2. Configured by field. The authority control status of each field is independently configured, but it affects all values of that field.
  3. Authority control can be optional or required. When optional, metadata values may take on values that did not come from the authority.

  4. Authority values are ubiquitous. Authority values are accessible by crosswalk

    Footnote

    Crosswalk in DSpace context is a functionality that allows DSpace metadata format to be translated to external formats.

    plugins, in the UI, through OAI-PMH, etc.

    • All of those context can detect whether a value is authority-controlled or not by testing for presence of an authority key.
  5. Text-based searching and indexing is unchanged. Since metadata values still have text values, the browse and search systems will work unchanged.
  6. Choice behavior decoupled. The selection and choice mechanisms can be invoked independently (e.g. in the submit UI) of authority control.

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We will consider adding an administrative UI to detect and list these metadata problems.

Display and CrosswalkCrosswalk  

Every metadata value potentially includes values for an authority key, and an authority confidence. They are only present when the field is under authority control, and when there is an actual authority value, otherwise they are absent (e.g. in the DIM XML representation) or null.

The presentation UI can call on a generic method to get the canonical display string for an authority key, but it is welcome to interpret it in custom code to present a more detailed view. For example, one site may want to customize their Item display so a personal name appears with a link to their page on the institution's social networking site, which it obtains through the authority key.

Dissemination crosswalks will crosswalks will also receive the authority key so they can pass that knowledge on through OAI-PMH, exported packages, and any other dissemination vehicles.

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There are symbolic constants (and corresponding String symblic names) for the confidence levels defined in the Choices class:

IconConfidence

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Confidence value (stored in metadatavalue)DescriptionMirage 2 Glyphicon rendering

Image Added

ACCEPTED600This authority value has been confirmed as accurate by an interactive user or authoritative policy

thumbs-up

Image Added

UNCERTAIN

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500Authority value is singular and valid but has not been seen and accepted by a human, so its provenance is uncertain

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cog

Image Added

AMBIGUOUS400There are multiple matching authority values of equal validity

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question-sign

Image Added

NOTFOUND300There are no matching answers from the authority

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thumbs-down

Image Added

FAILED200The authority encountered an internal failure in trying to match the valuewarning-sign

REJECTED

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100The authority recommends this submission be rejected

Image Added

NOVALUE

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0No reasonable confidence value is available

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ban-circle

Image Added

UNSET-1No confidence value has been set (default value in the DB table)remove

The icon rendering in the XMLUI Mirage 2 theme takes place in choice-authority-control.xsl.

Separation of Choices from Authority Control

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Since choice management and authority control affect the operation of the interactive submission pages, there is naturally some interdependence with that configuration as well. This table shows how the data type chosen for a metadata field affects choice and authority management:

input-type (from input-forms.xml)

'lookup' Presentation Style

'suggest' Presentation Style

'select' Presentation Style

Authority Control

onebox

yes

yes

yes

supported

twobox

yes

yes

yes

supported

textarea

yes

yes

yes

supported

name

yes

NO

NO

supported

date

NO

NO

NO

n/a

series

NO

NO

NO

not tested

dropdown

NO

NO

yes

NO

qualdrop_value

NO

NO

NO

NO

list

NO

NO

???

not tested

Other Restrictions

Plugins and "Select" Presentation Style

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Code Block
plugin.named.org.dspace.content.authority.ChoiceAuthority = \
  org.dspace.content.authority.SampleAuthority = Sample, \
  org.dspace.content.authority.LCNameAuthority = LCNameAuthority, \
  org.dspace.content.authority.SHERPARoMEOPublisher = SRPublisher, \
  org.dspace.content.authority.SHERPARoMEOJournalTitle = SRJournalTitle, \
  org.dspace.content.authority.SolrAuthority = SolrAuthorAuthority

Automatic Choice Authority from Configurable Submission value-pairs

The default configuration also includes a special self-named plugin that picks up all the value-pairs elements defined in your input-forms.xml configuration and makes them available as choice authorities (especially suitable for the select presentation style(smile):

Code Block
plugin.selfnamed.org.dspace.content.authority.ChoiceAuthority = \
  org.dspace.content.authority.DCInputAuthority

Some of the ChoiceAuthority instances available in the default configuration are:

  • LCNameAuthority - Sample Library of Congress (USA) name authority - NOT for serious use.
  • SRPublisher - Journal Publisher names based on SHERPA/RoMEO database
  • SRJournalTitle - Journal Titles based on SHERPA/RoMEO database

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The old addMetadata methods are still available, of course, although they have a new failure mode. Whent the field is authority-controlled they will call the field's configured ChoiceAuthority's getBestMatch() method to generate an authority key and confidence value. If the field is configured to require an authority key, an exception is thrown if getBestMatch() does't return one.

Changes to

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Metadatum

Add fields:

Code Block
public String authority;
 public int confidence;

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Any Theme for a DSpace using the Choice or Authority Control features must include the CSS declarations prototyped in the Reference theme. The corresponding images must also be available in your theme. All of the other elements (JavaScript, translations, etc) are implemented below the theme layer.

Installing the Prototype

Panel

OBSELETE: This section is no longer needed, the Choice/Authority implementation is now part of DSpace 1.6

Here is how to install the prototype on your system:

  1. Checkout from the the special "sandbox" on svn:
  2. Modify your dspace.cfg properties to enable choice and/or authority control on some fields. Unless you configure choice control, nothing will be any different. (See "Configuration" section above for details)
  3. Configure and build as usual:
    • Be sure to choose the Reference theme, otherwise you'll have to copy over the choice/authority additions to your chosen theme (see above).
  4. After the fresh install, convert the database schema to 1.6 by running the SQL statements in the file: Oracle: /dspace/etc/oracle/database_schema_15_16.sql or Postgres: /dspace/etc/database_schema_15_16.sql
  5. Start the webserver as usual.

Work To Be Done

This prototype needs a little additional work before it can be ready for merging into 1.6 source. I'm hoping there will be developers interested in volunteering since these tasks are not relevant to my site and I have no extra time for them:

  1. <s>Test and support on the PostgreSQL database.</s> done.
    • This should be a simple matter of porting the SQL statements and testing it, easy if you already have that database running.
  2. <s>Port UI changes to JSPUI. More challenging.</s> done, thanks to Andrea Bollini
    • I'm willing to advise a bit, but have no time nor much non-rusty expertise in JSPUI.

Comments?

Please use the Discussion page.