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WWW 7 Trip Report (with updates from W3C AC meeting)

Brian Kelly Email Address

UK Web Focus B.Kelly@ukoln.ac.uk

UKOLN

University of Bath

http://www.ukoln.ac.uk/UKOLN is funded by the British Library Research and Innovation Centre, the Joint Information Systems Committee of the Higher Education Funding Councils, as well as by project funding from the JISC’s Electronic Libraries Programme and the European Union. UKOLN also receives support from the University of Bath where it is based.

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Contents

• Introduction• Tim Berners-Lee's Keynote talk• W3C Tracks at WWW 7 Conference• Keynote on Java• Papers

• Search engines • Metadata• Characterisation • Markup

• Questions

See <URL: http://www.ukoln.ac.uk/

web-focus/> for trip report, these slides, etc.

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About the Conference

WWW 7 Conference:• Held in Brisbane, Australia from 14-18 April 1998• About 1,400 participants• Exciting new technology - RDF• See <URL: http://www7.conf.au/>• Conference papers online for short period

W3C Advisory Committee meeting:• Held in CERN, Geneva on 24/25 June 1998• Open to W3C AC member organisations (e.g.

JISC)

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Evolvability (1)

Tim Berners-Lee's opening keynote talk talked about "evolvability" of the web:

• Evolution of markup languages and data• Goal: version 1 software partially understands version 2 data.

• Based on "we will be smarter in the future"• Goal: version A software partially understands version B data.

• Based on "Others will be smarter than us"• Use web as the registry (decentralised evolution)

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Evolvability (2)

RDF (Resource Description Framework ):• See a document as a combination of logical assertions

• Draw conclusions by combining many documents

Global reasoning engines, based on RDF could be "devastating"

"Is there a green car for sale for around $15,000 in Queensland?"

"Get involved in RDF, XML, Schemas"

"Design for evolvability"

See <URL: http://www.w3.org/Talks/1998/0415-Evolvability/slide1-1.htm>

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W3C Tracks

W3C (World Wide Web Consortium):

• Gives update on W3C activities in the W3C Track at WWW Conferences

• Covers:– User Interface Domain

– Architecture Domain

– Technology and Society Domain

– Web Accessibility Initiative

• Talks available at <URL: http://www.w3.org/Conferences/WWW7/W3CTrack.html>

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HTML Futures

HTML Futures:• Talk given by Dave Raggett• HTML 4.0 now complete. Need to look at HTML

futures.• Workshop in US in May. See details, including

position papers at <URL: http://www.w3.org/MarkUp/future/>

• HTML Briefing paper due out shortly• See Dave's slides at <URL: http://www.w3.org/Talks/1998/0416-WWW7-HTML/>

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HTML Futures (2)

Mobile Computers• Importance of mobile computers (PDAs, phones,

car computers, etc.) NOTE Dearing report• Relationship with accessibility issues• Challenges:

– Small screens – Long round trip times

– Limited processing power / memory

• Solutions:– Abbreviations for headings

– Use of styles (rather than, e.g., tables)

– Expanding and collapsing outlines

– Aural and visual media (headings spoken, read body)

– HTML 4.0 and CSS 2.0

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Maths

MML:• Math(s) Markup Language• An XML Application• W3C Recommendation

agreed on 7 April 1998• Java and ActiveX renderers• Dave Raggett has written

an authoring tool (Windows 95)

• See <URL: http://www.w3.org/Math/>

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Architecture

Architecture Domain:• Promote coherent Web architecture

• Automate information management - If a decision can be made by machine, it should

Working on:• HTTP/1.1 and HTTP/NG• Jigsaw server (in Java, freely available)• XML• SMIL

See <URL: http://www.w3.org/Talks/1998/04/WWW7-Arch/>

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XML

XML:

• Extensible Markup Language

• Addresses HTML's lack of evolvability

• XML 1.0 Recommendation in Feb 1998

• Note well-formedness:Make end-tags explicit: <LI>...</LI>

Make empty elements explicit: <IMG .../>

Quote attributes <IMG SRC="logo" HEIGHT="20"..

Use consistent upper/lower case

• and valid: Need DTD

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XML

• Extensible:<PART>M-471</PART>

• Multiple names spaces:<?xml:namespace ns="http://foo.org/1998-001" prefix="i">

<P>Insert <i:PART>M-471</i:PART></P>

• Sharing document structures:– It's hard– It's necessary– It's worth it

See <URL: http://www.w3.org/Talks/1998/04/WWW7-XML/>

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XLink, XPointer and XSL

XLink will provide sophisticated hyperlinking missing in HTML:

• Links that lead user to multiple destinations• Bidirectional links• Links with special behaviors:

– Expand-in-place / Replace / Create new window– Link on load / Link on user action

• Link databases

XPointer will provide access to arbitrary portions of XML resource

XSL stylesheet language will provide extensibility and transformation facilities (e.g. create a table of contents)

EnglandFrance

<commentary xml:link="extended" inline="false"> <locator href="smith2.1" role="Essay"/> <locator href="jones1.4" role="Rebuttal"/> <locator href="robin3.2" role="Comparison"/> </commentary>

<commentary xml:link="extended" inline="false"> <locator href="smith2.1" role="Essay"/> <locator href="jones1.4" role="Rebuttal"/> <locator href="robin3.2" role="Comparison"/> </commentary>

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XML Deployment

Ariadne issue 14 includes article on "What Is XML?"

Describes how XML support can be provided:

• Natively by new browsers

• Back end conversion of XML - HTML

• Client-side conversion of XML - HTML

• Java rendering of XML

Examples of intermediaries

See http://www.ariadne.ac.uk/issue15/what-is/See http://www.ariadne.ac.uk/issue15/what-is/

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HTTP

HTTP/0.9 and HTTP/1.0: Made the Web popular Design flaws and implementation problems caused poor

performance

HTTP/1.1: Addresses some of these problems 60% server support, client & proxy support beginning Performance benefits! (optimised implementation

reduces packet traffic by 2/3) Is acting as fire-fighter Poor usage counting Not sufficiently flexible or extensible

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HTTP/NG

HTTP/NG:• Based on convergence of Internet protocols• Two W3C Working Groups:

Web Characterisations: Study Web usage and form requirementsNew log format for easier collection & anonymisation

Protocol Design: Redesign Web as distributed object application

• Transition to HTTP/NG will be gradual– Use of proxies– Layer HTTP/NG on top of HTTP/NG using POST

• Distributed searching as HTTP/NG application?• W3C Briefing Package due out on 7 July

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WAI

WAI (Web Accessibility Initiative):• Ensures web specs address accessibility issues

• Based on universal design principles

Authoring:• Page Author Accessibility Checklist and Guidelines

draft at <URL: http://www.w3.org/TR/1998/WD-WAI-PAGEAUTH-0203>

Software• WAI Accessibility Guidelines: User Agent draft at

<URL: http://www.w3.org/TR/WD-WAI-USERAGENT>

Note • JISC DISinHE project at Dundee University.

See <URL: http://www.disinhe.ac.uk/>

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Technology and Society

Domain activities cover:• PICS• Digital Signature Initiative• Privacy (P3P)• Metadata (RDF)• Security Interest Group• Public Policy Interest Group• Electronic Commerce Interest Group

See <URL: http://www.w3.org/Talks/1998/04/WWW7TandS/>

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MetadataMetadata - the missing architectural component from the initial implementation of the web

Metadata

PICS, TCN,

MCF, DSig,

DC,...

AddressingURL

Data formatHTML

TransportHTTP

Metadata Needs:• Resource discovery• Content filtering• Authentication• Improved navigation• Multiple format support• Rights management

Metadata Needs:• Resource discovery• Content filtering• Authentication• Improved navigation• Multiple format support• Rights management

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Privacy

P3P (Platform for Privacy Preferences):• Privacy concerns are a current barrier to Web

development (Note Tim Berners-Lee's interview in Australian press)

• P3P project developing methods for exchanging Privacy Practices of Web sites and user

• Documents on architecture and vocabulary available

• P3P1.0 draft spec released on 19 May 1998• See <URL: http://www.w3.org/P3P/>

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DSig

DSig (Digital Signatures initiative):• Key component for providing trust on the web• DSig 1.0 is based on PICS• DSig 2.0 will be based on RDF and will support

signed assertion:– This page is from the University of Bath– This page is a legally-binding list of courses provided

by the University

• Potential for use in authentication but:– Little activity in this area in W3C– Implementation would require expensive infrastructure

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RDF

RDF (Resource Description Framework):• Highlight of WWW 7

• Provides a metadata framework ("machine understandable metadata for the web")

• Based on ideas from content rating (PICS), resource discovery (Dublin Core) and site mapping (MCF)

• Applications include:– cataloging resources – resource discovery– electronic commerce – intelligent agents– digital signatures – content rating– intellectual property rights – privacy

• See <URL: http://www.w3.org/Talks/1998/0417-WWW7-RDF>

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RDFRDF:

• Based on a formal data model (direct label graphs)

• Syntax for interchange of data

• Schema model

Resource ValuePropertyType

Property

page.html £0.05Cost

11-May-98

ValidUntil

RDF Data Model

page.html £0.05

11-May-98

Property

Cost

InstanceOf

ValidUntil

ValuePropObj

Cost

PropName

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RDF Example

Example of Dublin Core metadata in RDF<?xml:namespace ns="http://www.w3.org/TR/WD-rdf/" prefix="rdf"?>

<?xml:namespace ns="http://purl.org/dublin_core/schema/" prefix="dc"?>

<rdf:RDF> <rdf:Description RDF:HREF="page.html"> <dc:Creator>John Smith</dc:Creator> <dc:Title>John’s Home Page</dc:Title> </rdf:Description></rdf:RDF>

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Browser Support for RDF

Mozilla (Netscape's source code release) provides support for RDF.

Mozilla supports site maps in RDF, as well as bookmarks and history lists

See Netscape's or HotWired home page for a link to the RDF file.

Trusted 3rd

Party Metadata

Embedded Metadata

e.g. sitemaps

Image from http://purl.oclc.org/net/eric/talks/www7/devday/Image from http://purl.oclc.org/net/eric/talks/www7/devday/

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Web Graphics

• Three submission made to W3C:• Web Schematics• PGML (Precision Graphics Markup

Language)• VML (Vector Markup Language)

• Scalable Vector Graphics (SVG) Working Group has been set up

• See <URL: http://www.w3.org/Graphics/Activity>

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Random Thoughts on Software Development for the WebKeynote talk by James Gosling:

• Positive about Java futures• "This is the year the performance problem

disappears." JIT compiler performance is close to C. Betters JVMs available (e.g. HotSpot).

• Java ports to PDAs, phones, smart cards, …

Q.How serious are browser incompatibility problems?

A. Netscape made serious error at one point. There are also bugs in IE. Java Plugin (was Activator) may enable a functioning JVM to be installed (note supports <OBJECT> tag). See http://www.javasoft.com/products/plugin/

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Research Papers218 papers submitted.

54 papers, 43 short papers, 13 posters, 5 doctoral consortium papers and 6 panel abstracts published

Brief comments on papers of interest to web software developers and information providers.

General themes:• Java was widely used to implement ideas• Several papers on analysis of link structures to

improve searching• "Intermediaries" seem to be an interesting concept

See <URL: http://www7.conf.au/programme/fullprog.html>

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Metadata Systems

Three papers.

Specifying Metadata Standards for Metadata Tool Configuration by Andrew Waugh, CSIRO, Australia

Excellent paper showing how the expense of producing metadata requires a generic metadata editor

The Limits of Web Metadata and Beyond by Massimo Marchiori, MIT, USA

This paper describes how fuzzy techniques can be used to automatically generate metadata for existing resources

Structured Graph Format: XML Metadata for Describing Web Site Structure by Liechto et al

Producing site maps based on linking and directory structures

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Importance of Link InformationStructure Graph Format: XML Metadata for Describing Web Site Structure describes the creation of interfaces based on linkage and underlying directory structure.

For demonstration of Java applet see <URL: http://www.isl.Hiroshima-u.ac.jp/projects/SGF/>

Automatic Resource Compilation by Analyzing Hyperlink Structure and Associated Text describes automated creation of Internet catalogues by analysis of link information. See <URL: http://www7.conf.au/programme/fullpapers/1898/com1898.html>

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Markup

An Extensible Rendering Engine for XML and HTML by Ciancarini et al, Bologna University

Describes how Java can be used to provide browser support for new HTML / XML tags<APPLET archive="displets.zip">

<PARAM NAME="def" VALUE = "

<TAG name='reverse' src='reverse.class'>

</TAG> "> ...

<P>Text is displayed as <REVERSE>white text on black</REVERSE>

See http://www.cs.unibo.it/~fabio/displet/

Example of an intermediary

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Search and Indexing Techniques

The Anatomy of a Large Scale Hypertextual Web Search Engine Brin & Page, Stanford Univ

• Describes Google, a large-scale search engine developed for research purposes

• Uses link information• Use of service and

feedback is encouraged

http://google.stanford.edu/

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Characterisation

Summary of Web Characterisation by Pitkow

An excellent review of web characterisation studies, including:

– Client studies– Proxies and gateways– Server– Websites

Some conclusions:No. of page requests per site Mode of 1!

Site popularity 25% of servers 85% traffic

Document life span About 50 days

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Observations

The following comments are made:• There were several papers on how link

information (e.g. "who is pointing to this page?") can be used to improve searching (e.g. Google) and user navigation (e.g. SGMapper).

• The possible importance of intermediaries for deploying new technologies to current browsers:

– In proxies (e.g. WBI)– In Java (e.g. displets, MML support)– In JavaScript (e.g. XML -> HTML / CSS)

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Deployment IssuesMore sophisticated deployment techniques can be adopted to overcome deficiencies in simple model

HTML resource

browserWeb server

Web server simply sends file to clientFile contains redundant information (for old browsers) plus client interrogation support

Server proxy

Client proxy

Intermediaries can provide functionality not available at client:

• DOI support• XML support• Format conversion

Intermediaries can provide functionality not available at client:

• DOI support• XML support• Format conversion

IntelligentWeb server

Original Model

HTML / XML /

databaseresource

Sophisticated Model

browser

HTML Validation serviceExample of an intermediary

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Conclusions

• WWW 8 to be held at Toronto in May 1999• WWW 9 to be held in Amsterdam in 2000• Call for papers for WWW 8 shortly• Closing date December 1998

• For information on WWW protocol

developments see uk-web-focus-w3c@mailbase.ac.uk list