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IMS Metadata in a Digital Library: Experiences from iLumina

IMS Member Exchange

November, 2001

David McArthur, Sarah Giersch & Marty McClelland

Funding provided by the National Science Foundation DLI-Phase 2, NSF Award #0002935A Digital Library of Reusable Science and Math Resourcesfor Undergraduate Education

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iLumina’s VisionThe situation:• e-learning will create a huge demand for high-quality digital

course content• Publishers will meet some of this demand through ebooks• Instructors will still need informal digital modules to complement

and tailor ebooks to specific courses

The opportunity:• The Internet now provides a scalable way to implement peer-

centric sharing of informal digital content• iLumina is a digital library that will realize this opportunity

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iLumina’s Main Themes• Featuring diverse, small-scale SMETE resources, especially ones

created by instructors• Promoting sharing, reuse and re-construction of resources through

selected services and tools• Using IMS’s rich and standard metadata to describe resources• Keeping the cost of metadata low: Simplifying the creation of new

metadata; efficient mapping of existing metadata• Making the benefits metadata high: Developing services

underpinned by IMS metadata (e.g., recommendations as well as search and browse)

• Implementing a partially centralized (metadata) and partly distributed (content) architecture

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What has iLumina Accomplished to Date?

• Implemented IMS metadata information model (v 1.2)• Developed metadata tools based on IMS model• Cataloged 700+ granular SMETE resources• Included 6 distinct collections in iLumina

– 3 resident (content and metadata in iLumina)

– 3 distributed (content remote and metadata in iLumina)

• Implemented essential library services (search, browse and contribute), underpinned by IMS metadata

• Began developing extended library services (collection display, review and ratings)

• Coordinated with SMETE.ORG for federated cross-repository search using common IMS/IEE LOM/DC Core element set

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Non-iLumina/IMS metadata

iLumina/IMS metadata

Digital Content

Existing Repositories

…CSTC SECDL Other

Individual Contributions

iLumina Open

iLumina

ContentReview

Cataloging Toolfinal

Informal Collections

UNCW Mathwright

…

Other

MappingTool

Cataloging Tool

Construction Services

Community Services

Search Services

User

metadata

Architecture Overview

RecommendationsPersonalizations

Formal peer reviewUser ratings/review

General forumsSuggestion Boxes

Flexible RetrievalBrowsing

Faceted SearchBasic Search

Resource IntegratorAuthor Cataloging

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AcquiringMetadata

Solutions to minimize the cost of metadata creation:

1) Require that a limited number of elements be completed (Title, Discipline)

2) Automate completion of some elements (Contributor)

3) Design efficient interfaces

4) Educate users through point-of-need help screens

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Finding Resources with Metadata

The elements available for Advanced Search are a subset of the elements on the Contribution Form.

iLumina offers users the ability to perform nuanced searches using different IMS metadata elements, their vocabularies and logical combinations of them.

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Extending Metadata Use

The Browse Page uses a limited number of IMS elements to organize navigation of library resources.

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Collection-level Metadata

iLumina makes collections of resources accessible via a collection-level metadata record.

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IMS Metadata Elements: The Good, the Questionable and the Missing

• Complete implementation of the IMS information model (v 1.2)• Selective support of elements in iLumina services

– Can import and export all IMS compliant metadata records– Creates metadata with only a subset of elements– Searches on a smaller subset

• Why selective use of elements? Many of the Educational elements appear not particularly well-defined

or useful for our contributors and end-users Some are not cost-effective unless gathered automatically Others, such as Rights, are inadequate for their implied task A few, like Annotation, would be better included in non-cataloging

metadata records

• Only two new elements added:– General.Thumbnail– Technical.MediaType

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IMS Vocabularies: Few Standards and Many Choices

iLumina changes from IMS Defaultnone lots

General.LanguageTechnical.FormatEducational.InteractivityTypeEducational.SemanticDensityEducational.ContextEducational.DifficultyRights.CostRights.Copyright…

LifeCycle.StatusEducational.InteractivityLevelEducational.IntendedEndUserRole

General.StructureTechnical.Requirement.TypeTechnical. Requirement.NameRelation.Kind

LifeCycle.Contribute.RoleTechnical.MediaTypeEducational.Learning- ResourceType

Few standards means:• Different communities will adopt multiple different vocabularies• Metadata tools must facilitate the easy change of vocabulary

schemas and the mapping of vocabularies

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General Metadata Results

Multiple metadata uses: IMS metadata may pay for its high production costs by underpinning multiple services– Search and discovery– Browsing– Collection-level discovery and comprehension– Formal reviews– Composite learning object description and production (?)

Less is more: Extended descriptions should be modularized, not bundled into core catalog records; this can improve functionality– Annotations and informal reviews and ratings are in separate dynamic

records– DRM for a resource is independent from core catalog metadata– Detailed agent profiles not embedded in entity values (vcards) Offload some description to other specs: Packaging, LIP, DR …

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<xml/><xml/>HTMLHTML

HTMLHTML

SQL Server 2000

XSLT

IIS web server

request

XSP: xml server pageCocoon:XML publishing

Tomcat:servlet engine

MS ASP

ASP

response

XSP

JDBC

ODBCresponse

System Architecture Diagram

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Implementation Tradeoffs

relational data base

windows platform

ASP

Microsoft technologies

spaghetti code

iLumina specific

existing skills

rapid development

xml flat file

any platform

Java

open source

XML/XSLT

reusable/generic tools

learning curve impact

ease of maintenance

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Database Design Considerations

• structure of metadata persistence• facilitate typical user searches• speed of search and data display• import of data from other repositories• export of data on demand• maintenance• data integrity• support IMS Metadata v1.2 specification

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Non-IMS DB Fields

• xml – metadata in IMS v1.2 xml format• xmltext – text only ( exclude tags ) of xml field• availability – yes/no• availability_description – ex: repository down for

backup• accepted_date – metadata is public when

accepted• last_modified_date – used for OAI harvesting• centity – table for agent xcard elements• mediatype – image, video, audio, executable....

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References and Sources

• Our project website: http://www.ilumina-dlib.org• Project papers on the site:

– JERIC: Towards a Sharable Digital Library of Reusable Teaching Resources: Roles for Rich Metadata. Journal on Education Resources in Computing (JERIC).

– JCDL: Developing Recommendation Services for a Digital Library with Uncertain and Changing Data. Joint Conference on Digital Libraries (JCDL)

– JLibAdmin: Library Services Today and Tomorrow: Lessons from iLumina, a Digital Library for Creating and Sharing Teaching Resources. Journal of Library Administration.