Tutorial on Semantic Digital Libraries (ESWC'2007)
Upcoming SlideShare
Loading in...5
×
 

Tutorial on Semantic Digital Libraries (ESWC'2007)

on

  • 12,902 views

Full stack of slides from our tutorial on semantic digital libraries from ESWC'2007

Full stack of slides from our tutorial on semantic digital libraries from ESWC'2007

Statistics

Views

Total Views
12,902
Views on SlideShare
12,564
Embed Views
338

Actions

Likes
6
Downloads
386
Comments
0

5 Embeds 338

http://semdl.info 328
http://www.slideshare.net 7
http://static.slideshare.net 1
http://translate.googleusercontent.com 1
http://www.linkedin.com 1

Accessibility

Categories

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

CC Attribution-NonCommercial LicenseCC Attribution-NonCommercial License

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

Tutorial on Semantic Digital Libraries (ESWC'2007) Tutorial on Semantic Digital Libraries (ESWC'2007) Presentation Transcript

  • Tutorial – Semantic Digital Libraries - Introduction - Sebastian R. Kruk , Bernhard Haslhofer, Philipp Nußbaumer , Sandy Payette, Tomasz Woroniecki
  • Tutorial overview
    • Who we are
      • Sebastian R. Kruk, DERI Galway – Ireland
      • Bernhard Haslhofer, University of Vienna - Austria
      • Phillip Nußbaumer, Research Studios - Austria
      • Sandy Payette, Cornell University – USA
      • Tomasz Woroniecki, DERI Galway – Ireland
    • Today we want to
      • give you a brief introduction to the Semantic Web, and show how SW is related to digital libraries
      • present existing semantic digital library systems
      • discuss the current problems and future directions of semantic digital libraries and get feedback from you
    • After this tutorial you will know
      • what is the semantic digital library system
      • existing solutions in various degrees of detail
      • how to run semantic digital library solutions on your machine
  • Tutorial Schedule Comparison and the future of SemDL 12:15 – 12:30 Existing solutions - JeromeDL 9:45 – 10:30 Conclusions, discussio n 16: 45 - 17: 3 0 Lunch break 12:30 – 1 4 : 0 0 Hands-on session (part I) 14:00 – 15: 3 0 Coffee break 15: 3 0 – 1 6 : 0 0 Hands-on session (part II) 1 6:0 0 – 16: 45 Existing Semantic Digital Libraries solutions 1 1:00 - 12: 15 Coffee break 10:30 – 1 1:00 Introduction to Semantic Digital Libraries 9:00 - 9 : 45 Time
  • Outline
    • Introduction to Semantic Web
    • Semantic Digital Libraries
  • The Semantic Web – A Brief Introduction
    • Current Web vs. Semantic Web?
      • An extension of the current Web in which information is given well-defined meaning, better enabling computers and people to work in cooperation. [Tim Berners-Lee]
      • Current Web was designed for humans, and there is little information usable for machines
    • Was the Web meant to be more?
      • Objects with well defined attributes as opposed to untyped hyperlinks between Internet resources
      • A network of relationships amongst named objects, yielding unified information management tasks
    • What do you mean by “Semantic”?
      • the semantics of something is the meaning of something
      • Semantic Web is able to describe things in a way that computers can understand
  • The Semantic Web – A Brief Introduction
    • Where are we in the “S emantic W eb layer cake”?
    You Are Here!
  • The Semantic Web – A Brief Introduction
    • The challenge for the Semantic Web
      • The Semantic Web can’t work all by itself
      • For example, it is not very likely that you will be able to sell your car just by putting your RDF file on the Web
      • Need society-scale applications: Semantic Web agents and/or services, consumers and processors for semantic data, more advanced collaborative applications
  • The Semantic Web – What is RDF ?
    • Describing things on the S emantic W eb
      • RDF (Resource Description Framework)
        • a data format for describing information and resources,
        • the fundamental data model for the Semantic Web
      • Using RDF, we can describe relationships between things like:
        • A is a part of B or
        • Y is a member of Z
        • and their properties ( size , weight , age , price …) in a machine-understandable format where each thing has a
      • RDF graph-based model delivers straightforward machine process ing
      • Putting information into RDF files makes it possible for “scutters” or RDF crawlers to search , discover , pick up , collect , analyse and process  information from the Web
  • The Semantic Web – What is RDF ?
    • A simple RDF example
      • Statement:
      • “ Stefan Decker is the creator of the resource (web page) http://www.stefandecker.org ”
      • Structure:
        • Resource (subject) http://www.stefandecker.org
        • Property (predicate) http://purl.org/dc/elements/1.1/creator
        • Value (object) “ Stefan Decker ”
      • Directed graph:
    http://www.stefandecker.org dc:creator Stefan Decker
  • The Semantic Web – How RDF can help us?
    • How RDF can help us?
    • identify objects
    • establish relationships
    • express a new relationship  just add a new RDF statement
    • integrate information from different sources  copy all the RDF data together
    • RDF allows many points of view
    • What is an Ontology?
      • „ An ontology is a specification of a conceptualization.“
    • Tom Gruber, 1993
    • Ontologies are social contracts
      • Agreed, explicit semantics
      • Understandable to outsiders
      • (Often) derived in a community process
    • Ontology markup and representation languages:
      • RDF and RDF Schema
      • OWL
      • Other: DAML+OIL , EER , UML , Topic Maps , MOF , XML Schemas
    The Semantic Web – Ontologies and Schemata
    • Defines small vocabulary for RDF:
      • Class, subClassOf, type
      • Property, subPropertyOf
      • domain, range
    • Vocabulary can be used to define other vocabularies for your application domain
    The Semantic Web – RDF Schema Person Student Researcher subClassOf subClassOf Jeen type hasSuperVisor domain range Frank type hasSuperVisor
    • OWL – The Web Ontology Language
          • Owl took Christopher Robin’s notice from Rabbit and looked at it nervously. He could spell his own name WOL , and he could spell Tuesday so that you knew it wasn’t Wednesday, and he could read quite comfortably when you weren’t looking over his shoulder and saying "Well?" all the time...
    • provides a vocabulary for defining classes, their properties and their relationships among classes.
    The Semantic Web – OWL owl :disjointWith s s s s Animal Herbivore Carnivore Omnivore
    • Based on Description Logics
    • OWL is a W3C Recommendation
  • The Semantic Web – Applications
    • Semantic Web cannot be and is not only a set of recommendations
    • Semantic Web is becoming reality by applications that support it and are based on it
    • Enabling technologies:
      • RDF Storages: Sesame, Jena, YARS
      • Reasoners: KAON, Racer
      • Editors: Protege, SWOOP, MarcOnt Portal
    • End-User applications:
      • Semantic wikis: Makna, SemperWiki
      • Semantic blogs
      • Semantic digital libraries
  • Outline
    • Introduction to Semantic Web
    • Semantic Digital Libraries
  • What is a Semantic Digital Library?
    • Semantic digital libraries
      • integrate information based on different metadata, e.g.: resources, user profiles, bookmarks, taxonomies – high quality semantics = highly and meaningfully connected information
      • provide interoperability with other systems (not only digital libraries) on either metadata or communication level or both – RDF as common denominator between digital libraries and other services
      • delivering more robust, user friendly and adaptable search and browsing interfaces empowered by semantics
  • Old days of hard-copy books
    • Library:
      • Archive (storage space)
      • Bibliographic cards (metadata)
      • Librarian (interface)
    • Pros:
      • Someone to talk to, to understand us, to explain, help in searching
    • Cons:
      • Based on physical location
      • Libraries are not connected – we have to visit every place
  • Yesterday of digital books
    • Digital library
      • Database and archive (storage)
      • Digital bibliographic descriptions (metadata)
      • Full-text search (interface)
    • Pros:
      • Content accessible online
      • Federations of libraries – visit less places
    • Cons:
      • Lonely user - n o one to talk to, we need to find the right keywords, what if we do not know them (“man without an ear” paintings example)
      • Still many problems with interconnecting (different) libraries
  • Today of interconnected content
    • Semantic Digital Libraries
      • Database and archive (storage)
      • Semantic bibliographic description (interconnected metadata)
      • Search and browsing on ontologies (interface)
    • Pros:
      • Search and browsing based on semantics can help in substituting the librarian
      • It is easier to interconnect heterogeneous libraries (RDF as common denominator)
    • Cons:
      • Semantics created from legacy formats – still hard to capture by most of average users
  • Tomorrow of social media
    • Social Semantic Digital Libraries
      • Database and archive (storage)
      • Bibliographic descriptions with annotations provided by users (metadata)
      • Collaborative search and browsing (interface)
    • Pros:
      • Users contribute to the classification process
      • Users can understand community driven annotations
      • Users enhance digital content using blogs, wikis on the side
    • Cons:
      • Not everyone is convinced
  • How are Semantic Digital Libraries different?
    • Semantic digital libraries extend digital libraries by
      • describing and exposing its resources in a machine ‘understandable’ way
      • resources can be
        • contents, digital artefacts
        • organization of objects (e.g. collections)
        • users, user communities
        • controlled vocabularies, thesauri, taxonomies
      • expose the semantics of their metadata in terms of an ontology
        • defined using a formal language
      • deliver mediation services for communication with other systems
  • Semantic Web Technologies for Digital Libraries?
    • Metadata is the key concept
    • the Web does not have metadata
      • the idea of a Semantic Web is nice but difficult to implement
    • many digital libraries do have metadata in place
    • we simply must make them available in a machine understandable format
    • the Semantic Web provides the format: RDF
  • Semantic Web Technologies for Digital Libraries?
    • Knowledge in bibliographic records
    • Digital Libraries already have controlled vocabularies, taxonomies or even ontologies in place
    • the challenge is to model this knowledge in a machine understandable way
    • the Semantic Web provides ontology language s:
      • RDF Schema
      • OWL
      • SKOS
  • A Sample Bibliographic Record Copyright 2000 The J. Paul Getty Trust & College Art Association, Inc . Terms taken from Controlled Vocabularies Vincent van Gogh; painter: Gogh, Vincent van (Dutch painter, 1853-1890) Creation-Creator/Role J. Paul Getty Museum Current Location-Repository Name irises , nature , soil , etc. Subject-Matter 1889, earliest: 1889, latest: 1889 Creation-Date Irises Title paintings Object/Work type Paintings Classification
  • Knowledge Organization Systems
    • tools that present the organized interpretation of knowledge structures
    • semantic tools - meaning of words and other symbols as well as (semantic) relations between symbols and concept
    • organize information and promote knowledge management
    • Examples:
      • classification and categorization schemata (organize materials at a general level)
      • subject headings (provide more detailed access)
      • authority files (control variant versions of key information such as geographic names and personal names)
      • highly structured vocabularies, such as thesauri
      • traditional schemes, such as semantic networks and ontologies
  • Taxonomy of Knowledge Organization Systems
    • Term Lists
      • Authority files ( FOAF )
      • Glossaries
      • Dictionaries
      • Gazetteers
    • Classifications and Categories ( DMoz )
      • Subject headings
      • Classification schemes
      • Taxonomies
      • Categorization Schemes.
    • Relationship Lists
      • Thesauri ( WordNet, MeSH )
      • Semantic networks
      • Ontologies
    (Hodge, 2000)
  • Understanding Knowledge Organization Systems
    • controlled vocabulary - a list of terms that have been enumerated explicitly
    • taxonomy - a collection of controlled vocabulary terms organized into a hierarchical structure.
    • formal ontology – a controlled vocabulary expressed in an ontology representation language. This language has a grammar for using vocabulary terms to express something meaningful within a specified domain of interest.
    • meta-model - an explicit model of the constructs and rules needed to build specific models within a domain of interest. A valid meta-model is an ontology, but not all ontologies are modeled explicitly as meta-models.
      • as a set of building blocks and rules used to build models
      • as a model of a domain of interest, and
      • as an instance of another model.
  • Simple Knowledge Organization Systems (SKOS)
    • basic structure and content of concept schemes such as
      • thesauri,
      • classification schemes,
      • subject heading lists,
      • taxonomies,
      • 'folksonomies ',
      • other types of controlled vocabulary
    • core concepts:
      • narrower and broader
      • isSubjectOf and subject ; isPrimarySubjectOf and primarySubject
      • member and Collection; memberList and OrderedCollection
      • related and semanticRelation
      • note, definition; altLabel and prefLabel ; symbol and altSymbol
  • Benefits of Semantic Digital Libraries
    • Problems of today’s libraries
    • rapidly growing islands of highly organized information
      • How to find things in a growing information space?
        • is it enough to have a full-text index (à la Google)?
        • typical “end-users” versus “expert users”
    • converging digital library systems
      • e.g. uniform access to Europe’s digital libraries and cultural heritage
  • Benefits of Semantic Digital Libraries
    • T he two main benefits of Semantic Digital Libraries
    • new search paradigms for the information space
      • Ontology - based search / facet search
      • Community-enabled browsing
    • providing interoperability on the data level
      • integrating metadata from various heterogeneous sources
      • Interconnecting different digital library systems
  • Searching the Sample Bibliographic Record
    • Full-text search
      • “ Paintings ” AND “ Van Gogh ” AND “ flowers ”  no result
    • Semantic query
      • if the knowledge that “ irises ” are “ flowers ” is modeled in an ontology (e.g. subclass-hierarchy)
      • we can query for all “ Paintings ” by “ Van Gogh ” with subject “ flowers ” and retrieve also the picture with subject “ irises ”
    Copyright 2000 The J. Paul Getty Trust & College Art Association, Inc . Vincent van Gogh; painter: Gogh, Vincent van (Dutch painter, 1853-1890) Creation-Creator/Role J. Paul Getty Museum Current Location-Repository Name irises , nature , soil , etc. Subject-Matter 1889, earliest: 1889, latest: 1889 Creation-Date Irises Title paintings Object/Work type Paintings Classification
  • Semantic Digital Libraries and Existing DL Systems
    • how to handle the legacy (meta-)data problem
    • lifting existing (meta-)data to a semantic level
      • simple solutions like MARC21  DublinCore
      • complex ontologies like MarcOnt Ontology for capturing concepts from different standards
    • legacy libraries expose their metadata via well established protocols - the metadata can be imported into semantic DLs
    • semantic DLs can play a role of integration champions in the information retrieval process in heterogeneous networks:
      • OAI-PMH
      • Z39.50
      • Dienst
  • Application A reas for Semantic Web T echnologies
    • Thesauri & Controlled Vocabularies
      • qualified DublinCore
      • DMoz, DDC-based taxonomies
      • SKOS, WordNet and other thesauri
    • Schema Mappings / Crosswalks
      • MarcOnt Ontology – aims to cover concepts from MARC21, BibTeX and DublinCore
      • MarcOnt Mediation Services – an open mediation framework between common legacy metadata standards
    • Metadata Integration
      • RDF as a common data model for integrating metadata from various autonomous and heterogeneous data sources
      • OWL for modeling the data source’s semantics
      • SPARQL as a common query language
  • Semantic DL as Evolving Knowledge Space
    • In state-of-the-art digital libraries users are consumers
      • Retrieve contents based on available bibliographic records
    • Recent trends: user communities
      • Connetea
      • Flickr
    • In Semantic digital libraries users are contributers as well
      • Tagging (Web 2.0)
      • Social Semantic Collaborative Filtering
      • Annotations
    • Semantic Digital libraries enforce the transition from a static information to a dynamic (collaborative) knowledge space
  • Existing Semantic Digital Library Systems
    • JeromeDL
      • a social semantic digital library makes use of Semantic Web and Social Networking technologies to enhance both interoperability and usability
    • BRICKS
      • aims at establishing the organizational and technological foundations for a digital library network in order to share knowledge and resources in the cultural heritage domain.
    • FEDORA
      • delivers flexible service-oriented architecture to managing and delivering content in the form of digital objects
    • SIMILE
      • extends and laverages DSpace, seeking to enhance interoperability among digital assets, schemata, metadata, and services
  • Tutorial – Semantic Digital Libraries - Existing Semantic Digital Libraries Solutions - Sebastian R. Kruk , Bernhard Haslhofer, Philipp Nußbaumer , Sandy Payette, Tomasz Woroniecki
  • Existing Semantic Digital Library Systems
    • JeromeDL
      • a social semantic digital library makes use of Semantic Web and Social Networking technologies to enhance both interoperability and usability
    • BRICKS
      • aims at establishing the organizational and technological foundations for a digital library network in order to share knowledge and resources in the cultural heritage domain.
    • FEDORA
      • delivers flexible service-oriented architecture to managing and delivering content in the form of digital objects
    • SIMILE
      • extends and laverages DSpace, seeking to enhance interoperability among digital assets, schemata, metadata, and services
  • Tutorial 7 – Semantic Digital Libraries - Existing Semantic Digital Libraries Solutions – JeromeDL Sebastian R. Kruk , Tomasz Woroniecki
  • Outline
    • JeromeDL - Motivation and Overview
    • JeromeDL - Architecture and Ontologies
    • JeromeDL - Semantic Services
    • JeromeDL - Social Services
    • JeromeDL - Semantics in Use
  • JeromeDL - Introduction
    • Joint effort of DERI, National University of Ireland, Galway and Gdansk University of Technology (GUT)
    • Distributed under BSD Open Source license
    • Digital library build on semantic web technologies to answer requirements from: librarians, scientists and everyone.
  • Motivation
    • How to integrate and search information from different bibliographic sources?
    • How to share and interconnect knowledge among people?
  • JeromeDL – Motivations Use Cases
    • Librarians:
      • support for rich metadata (MARC21) in uploading resources, accessing bibliographic information and searching
      • persistent identifiers
    • Scientists:
      • easy publishing (designed as a institute/university digital library)
      • creating hierarchical networks of digital libraries
      • support for accessing, sharing and searching using bibliography metadata (BibTeX)
    • Everyone:
      • simple search (incl. natural language queries)
      • community-aware information sharing and browsing,
      • support for interationalization
  • JeromeDL - Motivations
    • Support for different kinds of bibliographic medatata, like: DublinCore , BibTeX and MARC21 at the same time.
      • Making use of existing rich sources of bibliographic descriptions (like MARC21) created by human.
    • Supporting users and communities:
      • user s ha ve control over their profile information ;
      • community-aware profiles are integrated with bibliographic descriptions
      • support for community generated knowledge
    • Delivering communication between instances:
      • P2P mode for searching and users authentication
      • Hierarchical mode for browsing
  • Outline
    • JeromeDL - Motivation and Overview
    • JeromeDL - Architecture and Ontologies
    • JeromeDL - Semantic Services
    • JeromeDL - Social Services
    • JeromeDL - Semantics in Use
  • JeromeDL – Architecture
    • Resources and annotations repository
    • Middleware:
      • query processing
      • community space
      • resources management
    • User interface agents:
    • Communication to the outside world
    • Administrative interface
  • Bibliographic Description in JeromeDL <?xml version =&quot;1.0&quot; encoding =&quot;UTF-8&quot; ?> <rdf:Description rdf:about =&quot;http://...id=828374765&quot; > <dc:title> JeromeDL - Adding Semantic Web Technologies to DLs </dc:title> <dc:creator> Sebastian Kruk </dc:creator> <dc:description> In recent years... </dc:description> </rdf:Description> 01450cas 922004331i 450000100...019c19329999gw qr|p| ||||0 |0ger | a0044-2992 9a200412140219bVLOADc200404071525dvkulc200310071018dvbjc200303101205dkopumky200209211341zVLOAD aGD U/MPcGD U/MPdGD U/MFdGD U/KKsdWR O/EJ0 ager1 aZ. Kunstgesch. 0aZeitschrift für Kunstgeschichte00aZeitschrift für Kunstgeschichte.18aZfK aMünchen ;aBerlin :bDeutscher Kunstverlag,c1932-. c26-29 cm. aKwart.0 a1 Bd. (Juni 1932)-. aOpis na podst.: LCC. aW 1932 założycielami czasopisma byli Wilhelm Waetzoldt i Ernst Gall.... These all can be represented in RDF @ InProceedings { jeromedexa2005, author = &quot;Sebastian Ryszard Kruk and ... &quot;, title = &quot;{JeromeDL - Adding Semantic ...}&quot;, booktitle = &quot;{In Proceedings to DEXA 2005}&quot;, year = 2005}
  • Structure ontology in JeromeDL
  • Bibliographic (MarcOnt) Ontology in JeromeDL
  • Community-aware (FOAFRealm) ontology
  • Ontologies in JeromeDL
  • Metadata and Services in JeromeDL
  • Outline
    • JeromeDL - Motivation and Overview
    • JeromeDL - Architecture and Ontologies
    • JeromeDL - Semantic Services
    • JeromeDL - Social Services
    • JeromeDL - Semantics in Use
  • Semantic Metadata and Services
  • MarcOnt Initiative – Overview
    • Motivation:
    • Provide set of tools for
    • collaborative ontology
    • development
    • MarcOnt Initiative goals:
    • Create a framework for collaborative ontology improvement (E-learning)
    • Provide domain experts with tools to share their knowledge
    • Offer tools for data mediation between different data formats
  • MarcOnt Portal and MarcOnt Ontology
    • MarcOnt Ontology:
    • Central point of MarcOnt Initiative
    • Translation and mediation format
    • Continuos collaborative ontology improvement
    • Knowledge from the domain experts
    • MarcOnt Portal (source of knowledge):
    • Suggestions
    • Annotations
    • Versioning
    • Ontology editor
  • MarcOnt Mediation Services for Legacy Metadata Format translation RDF Translator Format co-operation MarcOnt Mediation Services
  • Browsing the data graph – why?
    • The search does not end on a (long) list of results
    • The results are not a list (!) but a graph
    • „ Lost in hyperspace”
    • A need for unified UI and services for filter/narrow and browse/expand services
    • Share browsing experience – navigate collaboratively
  • Browsing the data graph – how?
    • Defines REST access to services and their composition
    • Basic services: access, search, filter, similar, browse, combine
    • Meta services : RDF serialization, subscription channels, service ID generation ,
    • Context services : manage contexts, manage service calls/compositions in the context, lists contexts
    • Statistics services : properties, values, tokens
  • Browsing the data graph
    • JeromeDL exploits interconnected data
  • Browsing the data graph
    • … to allow browsing
  • Outline
    • JeromeDL - Motivation and Overview
    • JeromeDL - Architecture and Ontologies
    • JeromeDL - Semantic Services
    • JeromeDL - Social Services
    • JeromeDL - Semantics in Use
  • Semantic Metadata and Services
  • Social Services in JeromeDL
    • Involve users into sharing knowledge
      • Blogs – comments and discussions about documents and resources
      • Tagging – collaborative classification
      • Wikis – collaboratively edited additional descriptions, such as summaries and interesting facts
    • Preserve knowledge for future use
      • Users can learn from experience of others instantly
      • Recommend new, interesting resources based on users’ profiles
  • FOAF - Describing Social Networks
    • FOAF - Stands for Friend-of-a-Friend
    • Defines properties for a person (but it does not have to be a person, can be an “agent”)
    • Does not only have to contain one person per file
    • Can build a network of people with foaf:knows links
    • FOAF can be easily extended to meet requirements, as in the case of FOAFRealm for identity management…
  • Identity management with FOAFRealm
    • Identity defined with extended FOAF metadata
    • Policies expressed by social networking
      • Distance between owner and requester
      • Friendship level between owner and requester, calculated across digraph of social network
    • Support for single registration and sign on
    • Distributed identity management with HyperCuP (“D-FOAF”)
    • FOAFRealm is currently implemented as a plugin for Tomcat (Realm/Valve implementation), with PHP and .NET versions coming soon
  • Social Semantic Collaborative Filtering
    • Why?
      • The bottom-line of acquiring knowledge: informal communication (“word of mouth”)
    • How?
      • Everyone classifies (filters) the information in bookmark folders ( user-oriented taxonomy )
      • Peers share (collaborate over) the information ( community-driven taxonomy )
    • Result?
      • Knowledge “flows“ from the expert through the social network to the user
      • System amass a lot of information on user/community profile (context)
  • Social Semantic Collaborative Filtering
    • Problems?
      • The horizon of a social network (2-3 degrees of separation)
      • How to handle fine-grained information (blogs, wikis, etc.)
    • Solutions?
      • Inference engine to suggest knowledge from the outskirts of the social network
      • Support for SIOC metadata :
        • SIOC browser in SSCF
        • Annotations and evaluations of “local” resources
  • What is S ocial S emantic C ollaborative F iltering?
    • Goal: t o enhance individual bookmarks with shared knowledge within a community
    • Users annotate catalogues of bookmarks with semantic information taken from DM oz or WordNet vocabularies
    • Catalogs can include ( transclusion ) friend's catalogues
    • Access to catalogues can be restricted with social networking-based polices
    • SSCF delivers:
      • Community-oriented, semantically-rich taxonomies
      • Information about a user's interest
      • Flows of expertise from the domain expert
      • Recommendations based on users previous actions
      • Support for SIOC metadata
  • Social Semantic Collaborative Filtering foaf:knows xfoaf:include xfoaf:bookmark
  • Social Networks in Digital Libraries Resource xfoaf:Annotation user_C creator_B foaf:knows marcont:hasCreator creator_A foaf:knows foaf:knows xfoaf:Directory user_D xfoaf:owns xfoaf:linksTo xfoaf:isIn
  • Support for online communities in SSCF
  • Support for online communities in SSCF
  • Outline
    • JeromeDL - Motivation and Overview
    • JeromeDL - Architecture and Ontologies
    • JeromeDL - Semantic Services
    • JeromeDL - Social Services
    • JeromeDL - Semantics in Use
  • JeromeDL – Delivering Semantic Content
    • Providing semantic annotations during uploading process:
      • open module for handling any taxonomies
      • keywords based on WordNet and free tagging
      • defining structure of resources in the JeromeDL ontology
    • Lifting legacy metadata to MarcOnt ontology
    • Community maintained annotations
      • social semantic collaborative filtering
      • semantic descriptions based on the FOAF metadata
  • Annotating Library Resources
  • JeromeDL – Semantic Information In Use
    • Searching:
      • Keyword-based search with semantic query expansion
      • Semantic search:
        • Direct RDF quering
        • Natural language templates
    • Browsing
      • Exibit
      • MultiBeeBrowse
    • Sharing:
      • Social Semantic Collaborative Filtering
      • Semantically Interlinked Online Communities
    • Heterogeneous communication:
      • Bibster , A9 , OAI -PMH
  • Exposing Semantic Annotations
  • Filtering Resources in JeromeDL
  • Sharing Knowledge with SSCF
  • Information Retrieval in JeromeDL Fulltext Index Structure Repository MarcOnt Repository Resources’ Content FOAFRealm Repository (typed) keywords RDF & NL Query OpenSearch RSS collaborative filtering types translation semantic query expansion RDF Repositories Secure Snapshot local interface distributed interface
  • Networks of Digital Libraries
    • ELP (Extensible Library Protocol) implementation
      • communication within JeromeDL network
      • adapters for communication with other networks
    • D-FOAF integration (distributed user profile management)
      • single sign on and single registration within D-FOAF network
    • HyperCuP integration (scalable P2P network)
    • Independent ELP network entry point: http://search.jeromedl.org/
    0 0 1 1 0 0 1 1 0 2 2 2 2
  • Tutorial – Semantic Digital Libraries - Existing Semantic Digital Libraries Solutions – BRICKS Bernhard Haslhofer University of Vienna Austria Philipp Nußbaumer Research Studios Austria
  • Outline
    • BRICKS Overview
    • BRICKS Components
    • BRICKS Applications
  • What is BRICKS?
    • A software infrastructure for building digital library networks
      • Transparent access to distributed resources
      • Multilinguality
      • Easy installation & maintainance
    • A set of end-user applications
      • Network & content management
      • Web 2.0 tagging/annotations
      • Domain specific applications
    • A business model
      • Open source, platform independent
      • Low cost infrastructure
      • User communities  sustainability
  • BRICKS Architecture
    • A decentralized P2P network
      • Avoid central coordination
      • Highly Scalable, increased reliability
      • Minimized maintainance costs
    • Each P2P Node is a set of SOA components
      • Web Service interface
      • Platform independent
      • Flexible composition
    • Components for
      • Storing, accessing and protecting digital objects
      • (Semantic) search & browsing
      • P2P commmunication
  • Accessing Data
  • A Look into a BNode { BNode
  • Outline
    • BRICKS Overview
    • BRICKS Components
    • BRICKS Applications
  • Collection Manager
    • Single access point for all content and metadata related operations (local and remote)
    • Physical Collection
      • Similar to folder/directory hierarchy in a file system
      • Bound to a single BNode
      • Each digital content object belongs to exactly one collection
    • Logical Collection
      • Virtual folder for organizing content items independent of their physical location
      • Links to content items from various physical collections on different BNodes
      • A content item might belong to many of them
    • Stored Query similar to database views
  • Content Manager
    • Two ways to handle content in BRICKS
      • Stored locally at site of a member party, accessed via URL
      • Stored within BRICKS
    • Based on Java Content Repository (JCR)
    • Provides a meta-content model
      • Re-use of existing content models
      • Use standard models
  • Metadata Manager
    • Metadata descriptions  RDF
      • Suitable for any application scenario
      • Express relationships between objects
      • React to changes without changing the model
    • Schema defintions  OWL
      • No fixed schema
      • Extensible (e.g. Application profiles)
      • Semantic concepts instead of schematic strucutures
    • SPARQL
      • Metadata queries over ontology concepts
      • Queries for graph patterns
  • Security Manager
    • Transparently invoked by the Framework
      • any service call is checked
    • Context-aware policies based on RBAC (via XACML rules)
      • supporting Roles, Groups, at DLObject level
    • Permission declaration through Javadoc @tags
    • Federated identity is managed through an adapted version of OpenSAML
    • Reputation-based Trust calculation integrated
    • Web-based GUI for security configuration
  • Digital Rights Management
    • DRM Component
      • Support for licenses based on MPEG-21 REL license declaration standard
      • Generic API for the integration of commercial DRM systems
    • Watermarking
      • Open-source watermarking tool for images
      • Other tools can be integrated
    • BRICKS Store web application for commercial content
    • Creative Commons support for other content in BRICKS
  • Outline
    • BRICKS Overview
    • BRICKS Components
    • BRICKS Applications
  • Application: BRICKS Workspace
    • What does it demonstrate?
      • A web application (thin client) accessing BRICKS Foundation services
      • Web 2.0 image annotations
      • Reference application
    • Primary customers
      • General end-users (citizens)
      • Application developers
    • Technology
      • Struts based interface to the BCH
  • Application: BRICKS Desktop
    • What does it demonstrate?
      • A rich client application accessing BRICKS foundation services
      • Direct access to the BCHN
    • Primary customers
      • Expert end-users (researchers, educators)
      • Application developers
    • Technology
      • Eclipse based rich client interface
  • Application: Annotation Tool
    • What does it demonstrate?
      • Tool which allows end-users to annotate images
      • Creation of annotation threads
      • Supervised Annotations
    • Primary customers
      • End-users
      • Institutions with large image collections
    • Technology
      • Web Application
  • Application: Online Exhibition Authoring Tool
    • What does it demonstrate?
      • Creating and publishing online exhibitions using contents that is available in the BRICKS network
    • Primary customers?
      • Expert end-users (curators)
    • Technology
      • Web Application
  • Application: Archeological Finds Identifier
    • What does it demonstrate?
      • A web application for comparing findings (e.g. ancient coins) with objects in reference collections
      • Application of complex domain ontology (CIDOC-CRM)
      • Map visualization of GIS-Metadata
    • Primary customers?
      • Museum curators, archaeologists, students, amateurs,
    • Technology
      • Struts based interface
  • References
    • BRICKS Community Web Site
      • http://www.brickscommunity.org/
      • Main Contact: silvia.boi@metaware.it
    • Related (de-facto) standards
      • Resource Description Framework (RDF)
        • http://www.w3.org/TR/rdf-primer/
      • OWL Web Ontology Language (OWL)
        • http://www.w3.org/TR/owl-guide/
      • SPARQL
        • http://www.w3.org/TR/rdf-sparql-query/
      • Java Content Repository (JCR)
        • http://www.jcp.org/en/jsr/detail?id=170
    • Tools and Libraries
      • Jackrabbit
        • http://jackrabbit.apache.org/
      • Jena Semantic Web Framework
        • http://jena.sourceforge.net/
  • Tutorial – Semantic Digital Libraries - Existing Semantic Digital Libraries Solutions – Fedora Sandy Payette Director, Fedora Project Cornell University
  • Outline
    • Fedora
    • Examples: PLoS ONE and National Science Digital Library
  • Fedora Semantic Digital Libraries enable … Scholarly and Scientific Workbenches “ Web 2.0” Collaborative Repositories Museum Exhibits with Lesson Plans Linking Data and Publications blog and wiki
  • The Fedora Project
    • Fedora
      • F lexible
      • E xtensible
      • D igital
      • O bject
      • R epository
      • A rchitecture
    • History
      • Cornell Research (1997-2002)
        • DARPA and NSF-funded research and reference implementations
        • Distributed, Interoperable Repositories (experiments with CNRI)
      • Open Source Project (2002-present)
        • Andrew W. Mellon Foundation (2002-2009)
        • Joint development by Cornell University and University of Virginia
        • Transitioning into non-profit organization (Fedora Commons 501c3)
  • Arts and Humanities
  • Sciences Education
  • Fedora - Technology Integration Semantic Repository Enterprise Preservation
    • Information Networks
    • Contextualization
    • Relationships
    • Query
    • Inference
    • Workflow
    • Messaging
    • Transactions
    • Replication
    • Digital Objects
    • Manage
    • Access
    • Versioning
    • Storage
    • Integrity Check
    • Monitoring
    • Alerting
    • Migration
  • Fedora Digital Objects
    • Flexible object model can support
      • Documents, articles, journals
      • Electronic Scholarly Texts
      • Digital Images
      • Complex multimedia publications
      • Datasets
      • Metadata
      • Learning objects
      • More…
    • Create “networks” of objects using RDF
      • Define object relationships and other properties via RDF
      • Collection/member; part/whole; etc.
  • RDF in the Fedora Digital Object Model
  • Motivations: Fedora and Semantic Technologies
    • A natural model for exposing repository as network of objects
      • Object-to-object relationships
      • Relationships to external entities
      • Query the graph; traversal to discover related stuff
    • Indexing based on generalizable data model
      • Graph-based data model is a common reduction
      • Avoid fixed schema problems and metadata mud wrestling
    • Extensible enrichment of object descriptions
      • Keep overlaying statements from multiple ontologies
      • Organic evolution
    • Powerful queries and inference for repository management
      • Transitive relationships among objects
      • Dependency analysis;
      • Detection/Extraction of sub-graphs
      • Provenance of disseminations
  • Digital Objects contain their RDF assertions
    • Assert relationships from Fedora base ontology
      • Collection – member
      • Whole – part
      • Equivalence
      • Description Of
      • More…
    • Assert relationships/properties from community ontologies
      • isAnnotationOf
      • isRecommendedBy
      • isCertifiedBy
      • More ….
  • Example: Digital Objects with “compositional semantics”
  • Use Case: scholarly objects and annotation in the humanities musuem and library objects commercial web content scholarly objects URI-100 xx:recommends URI-55 yy:certifies
  • 3 Objects – 3 RDF “Relationships” Datastreams <rdf:Description rdf:about=&quot;info:fedora/uva:pid-11> <ais:annotationOf rdf:resource=“info:fedora/uva:pid-3”/> </rdf:Description> </rdf:RDF> <rdf:Description rdf:about=&quot;info:fedora/uva:pid-3&quot;> <uva:hasPartLetter rdf:resource=&quot;info:fedora/uva:pid-2&quot;/> <uva:hasPartDiagram rdf:resource=&quot;info:fedora/uva:pid-1&quot;/> </rdf:Description> </rdf:RDF> <rdf:Description rdf:about=&quot;info:fedora/uva:pid-10> <ais:providesContextFor rdf:resource=“info:fedora/uva:pid-3”/> </rdf:Description> </rdf:RDF>
    • NOT the core object store - RI is a graph-based index of the repository
    • Automatic, incremental indexing into triplestore
    • Search/query the repository via Fedora RI Query Interface
    Fedora RDF-based Resource Index (RI) RDF Index of Repository RDF datastream Fedora object properties DC datastream Digital Object Store
  • RI Graph - view 1 (abbreviated) …
  • RI Graph - view 2 (abbreviated) …
  • RI Implementation: The Triplestore Challenge
    • Scalability
      • Few triplestores perform well for 100M+ triples
      • Kowari – we tested to 180M triples
      • MPTStore – we tested to 250M triples
    • Performance
      • Jena - easy to get out of memory
      • Sesame Native - slow for complex queries
      • Kowari
        • Fast queries and full-featured query language (iTQL)
        • Instability and corruption problems
      • MPTStore
        • Very fast for SPO queries (limited support for complex queries)
        • Add/modify significantly faster than Kowari
      • Mulgara
        • Fork of Kowari; complex queries; models; inference
        • Major bug fixes to fix stability and corruption problems
        • XA2 transactions
        • Claims support for billions of triples
  • Fedora Repository – Notable Features
    • Generic Digital Object Model
    • Automatic content versioning and audit trail
    • Web Service Interfaces (REST and SOAP)
    • Authentication
    • Authorization
      • Flexible fine-grained policy enforcement
      • Built-in support for Extensible Access Control Markup Language (XACML)
    • RDF
      • Each object contains its own RDF assertions
      • Repository-wide index of all object (RDF triplestore)
    • Self-healing – rebuild repository via digital object source files
  • Outline
    • FEDORA
    • Examples: PLoS ONE and National Science Digital Library
  • PLoS ONE and Topaz Open Access Publishing and Collaboration
  • NSDL: Semantic Digital Library Architecture NDR
  • What is NSDL committed to?
      • NSDL 2.0 as a platform for a collaborative, contributory semantic digital library
      • Supporting communities across the full range of science, technology, engineering and mathematics research, learning and education
      • Supporting the creation of context around library resources to enhance discovery, use, and understanding
  • NSDL Semantic Digital Library repository requirements
    • Supports storing both content and metadata
    • Allows arbitrary relationships among resource and metadata objects: organization, annotation, citation
    • Accessible through web service architecture of remixable data sources and transformations
  • NSDL Data Repository (NDR)
    • Implemented in Fedora 2.2 with MPTStore
    • Moderately large
      • 4.7 million digital objects
      • 250 million RDF triples
    • Digital Objects
      • Resources
      • Metadata
      • Agents
      • Metadata providers
      • Aggregators
    • REST API and authentication
    • In production at nsdl.org
  • NSDL as Semantic Digital Library : collaboration, context, and contribution
    • Platform: Fedora repository and services
    • Applications:
      • Solution 1: Leverage the existing successful models: blogs, wikis, bookmarking/tagging
      • Solution 2: Leverage the existing software: WordPress, MediaWiki, Connotea, Sakai
      • Solution 3: Engage with partners and the broader community to build applications to the platform
  • Expert Voices - Blogs on top of Fedora
  • Expert Voices
    • NSDL Blogosphere (http://expertvoices.nsdl.org)
      • Topic-based discussions (e.g. forensics) linked to related library resources
      • A way for NSDL community members to become NSDL contributors of resources, questions, reviews, annotations, metadata
    • Technology:
      • Wordpress-based multi-user multi-blog application (open source, plug-in architecture)
      • Owner controls publication of entries as NSDL resources and visibility of comments (NSDL middleware and Shibboleth)
    • Blog Entries:
      • linked references to NSDL library resources
  •  
  •  
  •  
  • NSDL 2.0 – The Whole Ecosystem … Protocol: OAI-PMH HTTP REST NDR API STEM Collections Search Service Archive Service Fedora-based NDR
  • NSDL 2.0 and the Semantic Web
    • NSDL 2.0 applications situate resources in context, aiding both discovery and use
    • Users become contributors, adding new resources, ratings, annotations, and organizational structure – frequently as a side effect of using the library
    • Fedora-based semantic web technology organizes resources, ties context to content, maintains provenance, enables discovery, empowers the user, and powers the library
  • Fedora Web Site: www.fedora.info Community Open Source Tools: www.fedora.info/tools Fedora Wiki: www.fedora.info/wiki Tutorial: : http://openarchives.org/fedora/ESWC-Fedora.zip
  • Tutorial – Semantic Digital Libraries - Comparison and the Future - Sebastian R. Kruk , Bernhard Haslhofer, Philipp Nußbaumer , Sandy Payette, Tomasz Woroniecki
  • Outline
    • SIMILE – short overview
    • Comparison between existing solutions
    • Digital Libraries and Social Web
    • Semantic Digital Libraries Scenarios
  • SIMILE – Introduction
    • SIMILE - Semantic Interoperability of Metadata and Information in unLike Environments
      • joint project conducted by the W3C, HP, MIT Libraries, and MIT's Lab for Computer Science.
      • extends and laverages DSpace, seeking to enhance interoperability among digital assets, schemata, metadata, and services
      • Goal: Make metadata interoperability easier for digital libraries by providing useful tools for browsing, searching and mapping heterogeneous metadata in RDF [ MacKenzie Smith, MIT Libraries ]
  • SIMILE – Introduction
    • SIMILE :
    • enhances interoperability and provides end-user services:
      • for digital assets, arbitrary schemata, metadata and services.
      • across distributed individual, community, and institutional stores.
      • though the application of RDF and semantic web techniques.
    • implements a digital asset dissemination architecture based upon web standards
  • SIMILE – Delivered Components
    • Tools for Metadata Managers
      • Gadget - XML inspector
      • RDFizers - Batch tools to transform existing XML data into RDF
      • Solvent - Firefox extension for Javascript screen scraping
      • Welkin - Graphical tool to inspect/edit RDF graph
    • Tools for End-Users
      • Longwell - Web-based RDF faceted metadata browser
      • Piggy Bank - Firefox extension for personal information management of metadata in RDF
      • Semantic Bank - Web-based server that allows data publishing and sharing by individuals, groups, or communities
      • Exibit - lightweight structured data publishing framework
      • Timeline - AJAXy widget for visualizing time-based events
  • RDFizers - T ransform XML data into RDF
    • RDFizers - Transform XML data into RDF:
    • tools that allow to transform existing data into an RDF representation
    • List of RDFizers in SIMILE:
      • MARC/MODS  RDF
      • OAI-PMH  RDF
      • OCW  RDF
      • EMail  RDF
      • BibTEX  RDF
      • Flat  RDF
      • Weather  RDF
      • Java  RDF
      • Javadoc  RDF
      • Jira  RDF
      • Subversion  RDF
      • Random  RDF
  • Solvent - Java S cript screen scraping
    • Solvent - JavaScript screen scraping:
    • a Firefox extension that helps write Javascript screen scrapers for Piggy Bank.
    • Motivation:
      • Piggy Bank needs web pages to embed information in RDF .
      • Unfortunately , not many web pages embed or link to RDF information .
      • Piggy Bank is capable to execute a particular screen scraper on particular pages in order to &quot;extract&quot; the information it needs.
      • turn s a regular web page into a semantic web page, freeing the data from the page/site that contains it.
  • Solvent - Java S cript screen scraping
  • Longwell - RDF faceted metadata browser
  • PiggyBank
    • Firefox extension for managing metadata - Loads RDF into local Longwell server
    • Search and faceted browse of local RDF - Views defined by library, other users
    • Users can find, collect, annotate RDF - Can then publish for access by others
  • PiggyBank
  • SemanticBank
    • Semantic Bank use cases:
      • persist information remotely on a server
      • share information with other people
      • lets you publish your information, both in RDF or to regular web pages
    • f or individuals, groups, communities - e.g. conference proceedings
      • t he ability to tag resources creates a powerful serendipitous categorization
      • Longwell facetted browsing view of published information
  • Timeline
  • Exibit
  • Outline
    • SIMILE – short overview
    • Comparison between existing solutions
    • Digital Libraries and Social Web
    • Semantic Digital Libraries Scenarios
  • System Features Comparison General Properties JeromeDL BRICKS Fedora OS Support Any Any Any Hardware Requirements 500MB RAM, min 128MB HD 500MB RAM, min 100MB HD 500MB RAM, min 100MB HD Software Requirements Java 1.5, Tomcat 5.5, Sesame Java 1.4/1.5, Jena Java 1.5, Tomcat, Kowari/Mulgara or MPTStore Current Stage Research Stable version 2.0.1 Second Prototype Production Version 2.2 No. Installations 12+ ~ 8 ~50 monitored; large # of downloads unmonitored Support Model Open Source Open Source Open Source
  • System Features Comparison Architectural Aspects JeromeDL BRICKS Fedora Distribution Distributed searching (P2P), aggregated browsing (hierarchical) Fully decentralized (P2P) federation via nameresolver search services; Alvis P2P Architecture Granularity Low (main building blocks) High (many Components) High (core repository service with configurable modules; loosely coupled services) DB - Support Any Sesame-compliant backend Any Jena compliant backend MySQL, Postgres, Oracle, McKoi; Kowari/Mulgara
  • System Features Comparison Content & Metadata Aspects JeromeDL BRICKS Fedora Content Types All All All Content Models JeromeDL ontology Any Any Metadata Schema MarcOnt + extensions Any RDF/S & OWL schema Any XML Schema, RDF/S & OWL schema Query types Full-text, Filed-Search, Ontology-based, NL Query Templates Full-text, Field-Search, Ontology-based (sparql) Field Search, Ontology-based (itql, rdql, sparql, spo), Full-Text (Lucene or Zebra backed service)
  • System Features Comparison Security & DRM Aspects JeromeDL BRICKS Fedora Security Model FOAFRealm RBAC XACML Policy Granularity Resource Component, Method, Object Object, Datastream, Dissemination method DRM Model Fair use DRM under development MPEG-21 REL DRM Datastreams DRM Enabling Tool Support Watermarking
  • System Features Comparison Semantic Aspects & Community Features JeromeDL BRICKS Fedora Reasoning Recommendation engine based on Prolog Configurable inference engine Holding pattern; look to Mulgara; Tagging Free tagging, Wordnet-based Annotation middleware component middleware/apps (e.g., NSDL/NDR; PLoSONE/Topaz) Taxonomies Any (JOnto) Any Any Knowledge Sharing SSCF component via middleware upon BRICKS via middleware upon Fedora Communities SIOC and FOAF compli a nce
  • Outline
    • SIMILE – short overview
    • Comparison between existing solutions
    • Digital Libraries and Social Web
    • Semantic Digital Libraries Scenarios
  • The future - Social Semantic Digital Libraries
    • Why current (semantic) digital libraries are not enough?
      • digital libraries should not be for librarians only but for average people
      • they concentrate on delivering content/information, not on knowledge sharing within a community of users
      • digital libraries have lost human-part of their predecessors
  • The future - Social Semantic Digital Libraries
    • What could be the solution?
      • make users/readers involved in the content annotation process
      • allow users/readers to share their knowledge within a community
      • provide better communication between users in and across communities
  • The future - Social Semantic Digital Libraries
    • What is Web 2.0?
      • The Web where “ordinary” users can meet, collaborate, and share using whatever is newly popular on the Web (tagged content, social bookmarking, AJAX, etc.)
      • The term Web 2.0 was made popular by Tim O’Reilly: http://www.oreillynet.com/pub/a/oreilly/tim/news/2005/09/30/what-is-web-20.html
      • Popular examples include: Bebo, del.icio.us, digg, Flickr, Google Maps, Skype, Technorati, Wikipedia…
  • The future - Social Semantic Digital Libraries (3)
    • Web 2.0 focuses include:
      • The Web as a platform for social and collaborative exchange
      • Reusable community contributions
      • Subscriptions to information, news, data flows, services
      • Mass-publishing using web-based social software
    • Social software for communication and collaboration:
      • IM, IRC, Forums, Blogs, Wikis, Social Network Services, Social Bookmarks, MMOGs…
  • Social Semantic Information Spaces
  • Comparing Web 1.0 / Web 2.0 / Semantic Web 2.0 Semantic Social Networks Online Social Networks Buddy Lists, Address Books Semantic Social Information Spaces - - Social Semantic Digital Libraries Google Scholar, Book Search CiteSeer, Project Gutenberg Semantic Forums and Community Portals Community Portals Message Boards Semantic Blogs Blogs Personal Websites Semantic Search Google Personalised, DumbFind Altavista, Google Semantic Wikis Wikis Content Management Systems Semantic Web 2.0 Web 2.0 Web 1.0
  • Outline
    • SIMILE – short overview
    • Comparison between existing solutions
    • Digital Libraries and Social Web
    • Semantic Digital Libraries Scenarios
  • Geo, Time, and Machine Tagging
    • Geo-tagging for resources with a specific geographical location
    • Time-tagging – community driven process of assigning auxiliary multimedia content
    • Machine-tagging – ability to mix structured annotations into tags
    • ROI-tagging :
      • Regions of interest
      • ERP game
      • Asynchonous version with annealing of annotations for less frequently visited libraries
  • SDL in eLearning
    • One of potential sources of future e-Learning systems
    • On the verge between formal (libraries) and informal (communities) learning sources
    • Semantic interoperability with Learning Management Systems
    • Improve knowledge creation, delivery and sharing
  • SDL in Future Museums
    • Museums have physical objects
    • Should bind digital annotations with physical objects
    • Real-virtual tours
      • Start with real, guided tour
      • Ubiquitous browse through context information
      • Locate other exhibitions in the vicinity
      • Share your knowledge and experience with others, leave bread-crumbs for others
      • Get the most of the exhibition during your visit
  • Discussion – Feedback The Librarian from Unseen University in Ankh-Morpork (formerly Dr. Horace Worblehat)