XML Technologies and Scholarly Communication

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XML Technologies and Scholarly Communication

• William H. Mischo
• w-mischo_at_uiuc.edu
• Grainger Engineering Library Information Center
• University of Illinois at Urbana-Champaign
• The XML Workshop for Electronic Journals
• March 9, 2001

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Outline

• The Digital Library.
• Scholarly Information Environment.
• Distributed Information Environment.
• Illinois Collaborative projects.
• XML Technologies.
• Metadata and Linking Technologies.
• Publishing Trends.
• Future Issues.

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Topics

• Enabling technologies for scholarly
  communication.
• Vision(s) of scholarly communication (roles of
  intermediaries).
• Relationships between scholarly communication
  trends and XML technologies.
• Middleware tools DOI, OAI, XML.
• Portal and gateway tools, innovative search and
  discovery.

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Overview

• We now have the tools to pursue the grand
  challenges of Information Retrieval
• Standard retrieval environment (Web) and
  interface/client (Browser).
• Ability to perform standardized searching (HTTP
  Post/Get, SQL, Z39.50).
• Standard language for describing and transforming
  content and metadata (XML, XSLT, DC, RDF,
  Schemas).
• Standard transport mechanisms to connect
  heterogeneous content (HTTP, B2B, SOAP).

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XML and Publishers

• InfoWorld article on the Seybold Seminars
  Publishing 2000, Boston, February 2, 2000.
• Tim Gill of Quark the use of XML could lead to
  a drop in the cost of Web publishing by 30 to
  50 and a significant reduction in the time it
  takes to produce sites.
• Gill I dont believe that there is any
  innovation in print that is going to save us even
  10 in costs.
• Issues and Challenges remain.

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The Digital Library

• Digital, Virtual, Electronic Library as
  network-based library without regard to place and
  time.
• Tendency to apply term to collections and
  resources.
• Digital Collections vs. Digital Library.
• Emphasis on the integration of collections and
  services.
• Application of standards and protocols is
  important.

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Scholarly Communication Overview

• Web-based and publisher-centric.
• Heterogeneous Distributed Repositories.
• Value-added services and branding of journals.
• Reciprocal relationships between publishers.
• Cooperation on linking standards (DOI, CrossRef).
• Alternative publishing models - Academia,
  Preprint Servers, disintermediation.

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Full-Text Technologies

• Continuum of Web-Enabled technologies -- all
  presently being utilized.
• Evolving technologies and standards.
• Role and history of markup.
• XML its role and importance.
• The Smart Document.

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Distributed Information Model

• Diverse information environment in which we
  operate.
• Multiple elements, relationships and nodes.
• Need for gateway, interface, and navigation
  tools.
• Need for document representation, transmission,
  linking, and retrieval middleware tools and
  standards.
• Role of A I Services.

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Distributed Repository Issues

• Integration of discrete publisher repositories,
  locally loaded full-text, local and remote A I
  services, OPAC, Web resources, and local data.
• Issues for user access
• need to identify appropriate publisher
  repository, but presently interfaces are
  different and full-text and controlled vocabulary
  searching often not offered.
• A Is not full-text but offer controlled
  vocabulary, no links to full-text repositories.

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Distributed Repository - Needs

• Integration of discrete publisher repositories,
  locally loaded full-text, local and remote A I
  services, OPAC, Web resources, and local data.
• Support simultaneous searching of A I Services,
  Distributed Repositories, OPACs, Web search
  engines, local files. Integrate TOC, full-text.
• Remote Reference 24 X 7.
• Metadata harvesting, archiving.
• Local Resolver services for locally loaded or
  Aggregator Resources.

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Illinois Testbed Project

• Funded under DLI-I by NSF, DARPA, and NASA,
  1994--1998. Awards made to 6 universities.
• Large-scale Testbed, Distributed Repository
  models, evaluation, Web software.
• Funded under CNRI D-Lib Test Suite Program,
  19982001.
• Collaborating Partners Program. AIP, APS, ASCE,
  IEE, NRL, ASM, ACM, NTT Learning Systems,
  Elsevier.

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Illinois Testbed

• American Institute of Physics--APL, JAP, RSI
• 16,000 articles, 1995--.
• American Physical Society--PRL
• 10,000 articles, 1995--, weekly updates.
• ASCE Journals (25 titles)
• 9,000 articles, 1995--.
• IEE Proceedings and Electronics Letters
• 8,500 articles, 1993--.
• ASM (American Society for Materials) Handbook.
• ACM (Association for Computing Machinery)
  Transactions.
• Elsevier Science.

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Project Issues

• Evolution of the Document.
• Distributed information environment.
• Use of Metalanguages Transformations (SGML,
  XML).
• Searching over full-text of journals vs. document
  surrogates in A I format.
• Rendering and styling (SGML, XML, MathML).
• Dynamic metadata for normalization, linking.
• Breadth and depth of collections.
• User needs.

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Accomplishments

• Process retrieve from multiple publishers
  heterogeneous DTDs.
• Cross-repository searching (Testbed D-LIB Test
  Suite).
• SGML to XML Conversion.
• Use of XML, XSLT, CSS, Metadata Schemas.
• Transformation rendering, including
  Mathematics.
• Dynamic Linking Forward/Backward, from/to A I
  Services. Local Resolver.

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Ongoing Investigations

• Support simultaneous searching of A I Services,
  Distributed Repositories, enhanced navigation,
  expanded gateway functions.
• Metadata harvesting replicative or distributed
  Approaches.
• Z39.50 protocols, HTTP harvesting, Spider
  technology.
• Archiving.
• Local Resolution of resources.

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XML (eXtensible Markup Language)

• Like SGML, a Data Description Language
  (Metalanguage).
• Subset/version of SGML.
• Allows fine-granularity markup of content and
  structure. Author can create their own elements
  (extensible).
• Tags define the structure of document not
  presentation format.
• All XML must have well-formed document structure,
  but may be validated against a DTD or Schema.
• Compatible with relational DBs.

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XML Features

• The milestones in document description and
  transmission ASCII, TCP/IP, HTTP and HTML, XML.
  Web Programmability.
• DTD not required with XML. Needed if internal
  entities.
• Use of Document Object Model (DOM).
• Technology approach from Web developers
  standpoint XML data, CSS presentation layer,
  XSLT to transform the structure (view) of the
  data/document.

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Role of XML

• If you ask 20 people in the industry, what is
  XML? Youll get 20 different answers Dale
  Fuller, CEO, Inprise Corporation.
• Vendor-Neutral, platform-independent structured
  information standard.
• Document representation and interchange Standard.
• Applications can externalize their data as XML.

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XML Parser APIs Tree-Based and Event-Based

• DOM (Document Object Model).
• DOM Level 1 and Level 2 W3C recommendation.
  Widely implemented, Tree-Based. Hierarchy of
  nodes. Loads entire document into memory. Level 2
  adds namespace support, traversal, stylesheets,
  events, triggers. Level 3 working draft. DOM HTML
  candidate. Parsers allow developers to iterate
  through documents, change document content.
• SAX (Simple API for XML).
• Open-source, XML-DEV, not W3C. Event-based, fires
  events as it reads document, need not load entire
  document into memory. Good for single-pass
  processing. Xerces, XML4C, Sun Project X
  (Crimson).

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XML Linking

• XML Base http//www.w3.org/TR/xmlbase
• Permits use of relative URI path prefixes. Can
  then shorten references.
• XLink http//www.w3.org/TR/xlink/
• Method for specifying navigational links. Allows
  enforcement of specific path order through links.
  xlinktypesimple corresponds to HTML ltagt or
  ltimggt tags.
• XInclude http//www.w3.org/TR/xinclude
• Copies entire XML documents or selected portions
  into current document. Candidate recommendation.
  Uses XPath and XPointer to specify document
  elements to include.
• XPointer http//www.w3.org/TR/xptr
• Uses XPath to identify portion of a document.
  Permits string searches and range specifiers.

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XML Schema and Structure

• DTD
• Original schema representation, defines
  structural rules for a class of XML documents.
• XML Schema http//www.w3.org/XML/Schema
• Also sets out standardized structure for class of
  XML documents. Is coded in XML, can be parsed and
  edited with standard software. Two separate
  parts structures and datatypes.
• Namespaces http//www.w3.org/TR/REC-xml-names/
• Allows developers to qualify element and
  attribute names with unique URIs, avoids
  recognition errors.

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XML Implementations

• XHTML, SVG (Structured Vector Graphics), XForms
  (similar to HTML forms).
• MathML http//www.w3.org/Math/
• Markup language for describing mathematics, both
  presentation and content.
• RDF http//www.w3.org/RDF/
• Resource Description Framework. Defines
  structure for encoding object metadata.
  Facilitates metadata interchange harvesting.
• Others DocBook, XML ISO12083, Open eBook,
  WAP/WML.

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Searching and Transformation

• XPath http//www.w3.org/TR/xpath
• Defines pattern-matching syntax used by XSLT and
  XPointer. Method for selecting data in a
  document. MSXML 3.0 supports XPath. Supercedes
  XPatterns./descendant-or-selfnode()/childname
  
• XSL
• Includes transformative and FO formatting
  objects. FO will replace CSS for document
  formatting.
• XSLT http//www.w3.org/TR/xslt
• Mechanism for encoding style rules, ensures
  consistent rendering of XML documents of the same
  type.
• XML Query http//www.w3.org/XML/Query
• Response to limitations of XPath. Would bring
  database-style queries to XML documents.

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Remote Object Access

• SOAP (Simple Object Access Protocol)
• Microsoft, IBM, Sun. Allows applications to
  invoke objects or functions residing on remote
  servers. Creates request block in XML.
• XML-RPC http//www.xmlrpc.com/
• Remote procedure calling using HTTP as the
  transport and XML as the encoding. Open, but not
  standard protocol widely adopted.
• Web Services.

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Remote Object Access

• Web Services
• Based on XML, SOAP, UDDI (Universal Description,
  Discovery, and Integration), and WSDL (Web
  Services Description Language). Applications are
  assembled on the fly in XML and accessed via the
  Web from different devices.
• Supported by Microsoft .net, IBM WebSphere, SUN
  ONE.

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XML, XSLT, and CSS

• Use XML full-text articles as ordered hierarchy
  of content objects.
• Generate item-level metadata in XML, using RDF
  and Dublin Core syntax and semantics.
• XSLT and CSS used to present metadata and
  articles in either XML or HTML format depending
  on Browser.
• Mathematics rendering using XML and CSS (MathML
  conversion beginning).
• Real-time transformation between XML and HTML
  using XSLT (scalability issues).

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XML Issues and Problems

• Variation in interpretation of parsing technology
  and varying implementations of schemas and need
  for standardized Schemas from DTDs.
• You don't know whether your data will be viewed
  in a Web browser, cell phone, or read by a parser
  on a household appliance (lttoaster_settinggtlight
  brown lt/toaster_settinggt)developer needs to
  comply with a common standard.

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Schemas vs. DTDs

• Both are systems of representing a data model
  that defines the datas elements and attributes,
  and the relationship among elements.
• Schema addresses limitations of DTDs and the
  increasingly data-oriented role of XML.
• Initial Arbortext, DataChannel, Inso, Microsoft,
  and Univ of Edinburgh proposal XML-Data.
• W3C XML Schema Working Group two documents XML
  structures and datatypes.

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Schema Justification

• Description of document types structure should
  be in an XML document instead of written in
  special syntax (DTD).
• Schema are in XML easier to edit and process
  using standard XML DOM manipulation tools.
• DTD notation doesnt allow schema designers the
  power to impose strong data typing -- for
  example, the ability to say that a certain
  element type must always have a positive integer
  value, that it may not be empty, or that it must
  be one of a list of possible choices.

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Metadata and Linking Standards

• Digital Object Identifier (DOI) and Persistent
  Object Identifiers.
• OpenURL and Value-Added Service Components (SFX).
• Open Archives Initiative (OAI), Dublin Core and
  Qualifiers.
• Local Resolver Servers.

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Metadata in DLI

• As Document (not Object) surrogate.
• To normalize augment presentation.
• To normalize searching (e.g. Names).
• To store dynamic links.
• Types of links
• Articles referenced By item (Backward).
• Articles that reference the item (Forward).
• A I Records for references and items.
• Other relationships (TOC, Other items by Author,
  Collaborative Data).
• Known item and presumptive linking.

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DLI Metadata Schema

• Maintained as XML files using RDF and Dublin Core
  syntax and semantics.
• Example
• ltdcSourcegt
• ltidlipublication typejournal articlegt
• ltidlijournal_titlegtApplied Physics
  Letterslt/idlijournal_titlegt
• ltidlivolumegt70lt/idlivolumegt
• ltidliissuegtlt11lt/idliissuegt
• ltidlipaginationgt1372-1374lt/idlipaginationgt
• lt/idlipublicationgt
• lt/dcSourcegt
• Application of XML DOM for processing at DC or
  idli level.

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Digital Object Identifier (DOI)

• DOI is both a unique identifier of a piece of
  digital content AND a system to access that
  content digitally. Persistent object identifier.
• The ISBN for the 21st Century -- Norman Paskin.
• DOI system has two main parts (the identifier
  and a directory system) and a third logical
  component, a database.
• Developed by AAP (Association of American
  Publishers), now managed by International DOI
  Foundation.

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DOI Construction

• First real open standard for content
  identification.
• DOI is a number that identifies a digital object
• 10.1063/S000369519903216
• 10 Registration Agency Prefix
• 1063 Publisher Prefix
• S000369519903216 Suffix (Publisher-assigned
  ID)
• Suffix can be SICI or PII.
• The DOI and URL pointing to the digital object,
  is registered with the International DOI
  Foundation, e.g
• 10.1063/333 http//www.pubsite.org/apr99/artl1.p
  df

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Using a DOI

• DOIs are resolved using the Handle System
  technology from CNRI (Corporation for National
  research Initiatives).
• Retrieval of object is two step process link is
  sent to central directory where current Web
  address is stored, location is sent back to
  browser with special message to redirect to
  address, e.g
• dx.doi.org/10.1063/333 redirects to
  www.pubsite.org/apr99/artl1.pdf

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Reference Linking

• Alternatives to DOI
• PubMed/PubRef (National Library of Medicine)
• PubSCIENCE (DOE/OSTI)
• Proprietary Link Managers (AIP, APS)
• CrossRef Project major Sci-Tech professional
  societies and commercial publishers.
• System design calls for one URL for each DOI
  underlying technology can handle multiple URLs
  however.

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Local Resolver

• Issue Directing users to locally held or
  licensed version of Digital Object (locally
  loaded or from Aggregator).
• Harvard problem, Appropriate Copy problem.
• Additional desire to direct users to local
  value-added services local print holdings,
  interlibrary borrowing, other articles in A I
  Services.

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Local Resolver

• Local Resolver Servers
• OpenURL Protocol, CookiePusher vs. IP Addresses.
• Demonstration Project at Illinois, OhioLink (Ex
  Libris SFX), Los Alamos.
• Localizing Name Resolution for AIP, ASCE,
  Elsevier, other publishers.
• Use of CrossRef Metadata Database for identifying
  Publisher from DOI and linking to Local Copy, A
  I Services, Library Assistance.

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Open Archives Initiative (OAI)

• Released version 1.0 of metadata harvesting
  protocols. Frozen through second quarter 2001.
• Mechanism for data providers to expose their
  metadata through an HTTP protocol and a mechanism
  for harvesting records containing metadata from
  repositories.
• Roots in e-print archives.
• Lightweight, low-barrier. Easy to implement Web
  server to handle OAI protocol requests need to
  develop procedures to access and extract your
  metadata.

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OAI Continued

• Requires repositories to support the Dublin Core
  elements.
• Allows communities to expose metadata in other
  formats as long as records are structured as XML
  data with corresponding XML schema.
• Registration mechanism provides publicly
  accessible list of OAI conformants.
• Alpha testing phase completed.

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Computer Technologies

• XML Appliances Intel XML Accelerator.
• Thin Desktops
• Legacy-free PCs
• Network appliances (Sun Rays).
• Ubiquitous Computing
• Pocket PCs, PalmPilots, appliance devices.
• Wireless technologies.
• Peer to Peer Computing.

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Publishing Trends

• Publishers will continue to add value to online
  journal articles.
• Digital version will become version of record.
• Virtual journals (both publisher-based and
  cross-publisher) will become common.
• Next-generation knowledge environments will
  evolve. Multimedia, data exposed, live
  equations with in-place calculations.

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Publishing Trends (Continued)

• Personalized services will be available -- agent
  technology, alerting services.
• Different economic and subscription models will
  be introduced.
• Deconstruction of Journal (Bob Kelly, APS)
  article at a time publishing.
• Journal branding or perhaps publisher branding.
• Academia issues publishing, tenure.

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Closing Issues

• Role of Authors, Academic Institutions,
  Libraries, Publishers, Abstracting Indexing
  Services.
• Disintermediation may affect both Libraries and
  Publishers.
• Information as Function not Place.
• Provide a Digital Library out of digital
  collections.
• Role of XML technology.
• Service mechanisms processing archiving,
  search and discovery, presentation, linking.