Parallel Session on Metadata The Value of Metadata and how to Realise it.. Date 18 th June 2002...
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Transcript of Parallel Session on Metadata The Value of Metadata and how to Realise it.. Date 18 th June 2002...
Parallel Session on Metadata
The Value of Metadata and how to Realise it..
Date 18th June 2002
Facilitator: Dennis Nicholson
Centre for Digital Library Research
Notes and Slides
Theme: Examine, Discuss:
.…the value of using metadata as a aid to reliable retrieval both within individual Web sites and across distributed sites
….what the barriers to effective use of metadata are and how they can be overcome
….Who should be responsible for creating and maintaining metadata - resource creators; web-masters; librarians?
Theme: Examine, Discuss:
….Whether embedding and harvesting or a central database is the best approach.
…plus (if time allows): A step beyond, the value of Content
Management Systems Focus: General My background...
Responsibility to...
Stimulate: Thought; Discussion; Debate
Draw out the important points Impart ability to apply what we’ve
discovered Ensure participation So…
Individual needs and circumstances?
Effective Retrieval
What is it? Balance of precision and recall best
suited to a given problem High precision and low recall usually
preferred but in some cases (e.g. patents) there may be an advantage in lowering precision to boost recall
Level of precision and recall should be under the user’s control not a side effect of poor metadata
Effective Retrieval
Why does it matter? Costs University, public purse to
create the material - a waste if the people it is aimed at can’t find it
Strategic/PR considerations - If they can’t find your courses or expertise registers or digital images for sale if and when you want or need them to they won’t use you or talk or write about you
Effective Retrieval
When does it matter? Only if it is ‘stuff’ you want found The bigger they come, the sooner
they fail… The more ‘stuff’ you have, the more
campuses, or organisations in a collaboration,the harder it is to ensure effective retrieval
Especially with no or poor metadata
What is metadata?
Metadata is data about data Consists of things like:
Author; Title; Subject; Description; Level; Language; Viewer
Appropriate to function The route to effective retrieval Maybe...
What can go wrong?
Limited penetration (i.e. only some available documents covered) Misleading results for users
Different metadata record formats Can the software cope? Is there a
cross-walk? Incompatible core field sets
Cross-walk not possible
What can go wrong?
Different field sub-sets used (Both use DC but different field set) Full service limited to common fields
Different fields used for same data element (I put subject headings in subject field and free form keywords in the keyword field but you put subject headings in the keyword field) Misleading results
What can go wrong?
Different or no standards applied in creating data element content (e.g. Darwin, C. or Charles Darwin) Reduced retrieval; varied results
Different or no subject schemes and/or category lists (Educational levels, LCSH v. UNESCO v. made up) Reduced retrieval; varied results
Insufficient granularity (If everything physical is ‘physics’) Poor precision, high recall
What can go wrong?
Varied or no methods of central co-ordination (2 sites or campuses) Can cause some of the other
problems listed above and below Different sites index different fields
(One has subjects, keywords in one index, another in separate indices) Misleading for users
What can go wrong?
Missing indices (Nothing on the subject in the index or no subject index? (2 sites)) Misleading retrieval
Humans can cope but machines can’t (A machine finds it harder to ‘spot’ different usages of the ‘same’ word or alternative words for the same thing than a human does) Semantic web won’t work
Safeguards against:
Limited penetration Policy? Training? DC Dot? Human monitor?
Different formats Discover need, agree policy, set standards,
ensure software can cope with formats
Incompatible core field sets Identify formats (DC, IMS, MARC?) then
agree core set of fields (e.g. 15 in DC base)
Safeguards against:
Different field sub-sets used Agree, monitor, one core set
Different fields used for same data element Templates and examples, Central
co-ordination, Guidelines, Training
Safeguards against:
Different or no standards applied in creating data element content Template with examples
Different or no subject schemes and/or category lists Agree single schemes or lists, have
drop down lists, upgrade centrally
Safeguards against:
Insufficient granularity Agree usable level, training, examples
Varied or no methods of central co-ordination (2 sites or campuses) Make sure it doesn’t happen!
Different sites index different fields Agree approach, implement and
monitor standards
Safeguards against:
Missing indices Agree not to do this, and warn users if
you can’t agree Humans can cope but machines
can’t (semantic web) Use standard schemes, ontologies in
standard ways and map between different ones in a way that your software can process
Where to keep it?
Pros and Cons of: Embedding and harvesting:
Metadata creation more likely? Harder to co-ordinate, easier to resource? More often out of date? Harder to ensure standardised metadata?
A central database Easier to co-ordinate, more expensive to
resource? Easier to maintain standards? How to ensure new stuff notified?
Where to keep it?
Pros and Cons of: A mix of the two?
Worst of both worlds? Or best? How to ensure the latter? Optimise author input of embedded metadata but allow central upgrades by metatada experts? I this feasible? Is it cost-effective?
Depends on other factors? A question of designing to be fit for
purpose?
Whose Responsibility?
Candidates; Their pros and cons: Resource creators?
Au fait with the resource; Labour saving Web-masters?
Au fait with the technical landscape Librarians?
Au fait with knowledge and metadata domains Public Relations?
Au fait with the needs of the University
Anybody else? All of the above? Co-ordinated by?
Other Related Issues
A CMS would ensure : Currency; Accuracy; Legality; Authority of
Content retrieved by metadata
Not to mention Uniform look and feel control; easy total
redesign and global changes; all content tracked; joint authorship across departments, units, different institutions; easy repurposing
All who have some responsibility can be involved in controlled way?
Facilities
It would provide: Content authoring; collaborative
authoring; editing and workflow; preventing unauthorised editing or creation; scheduling publication; tracking changes; personalising; repurposing; metadata creation; knowledge management through semantic control
Closing Discussion…
Who has/plans to have a CMS? What does it/will it cost? Are they:
Essential? Optional? Impractical? A threat to academic freedom?
Do they help solve the metadata problem?
Useful URLs
Metadata http://content.lib.washington.edu/METADATA/ (Why should we care?) http://www.ukoln.ac.uk/metadata/dcdot/ http://www.ukoln.ac.uk/web-focus/metadata/seminar-materials/exercises/d
c-dot/dc-dot.doc
http://www.ukoln.ac.uk/metadata/dcassist/
Content Management Systems http://www.ukoln.ac.uk/nof/support/help/papers/cms.htm (what are
they?) http://www.ariadne.ac.uk/issue30/techwatch/ (Who needs them?) http://www.cultivate-int.org/issue5/cms/ (CMS’s available)