WWW 7 Trip Report
(with updates from
W3C AC meeting)
Brian Kelly
UK Web Focus
Email Address
B.Kelly@ukoln.ac.uk
UKOLN
University of Bath
http://www.ukoln.ac.uk/
1
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.
Contents
See
<URL: http://www.ukoln.ac.uk/
web-focus/> for trip report,
these slides, etc.
• Introduction
• Tim Berners-Lee's Keynote talk
• W3C Tracks at WWW 7 Conference
• Keynote on Java
• Papers
• Search engines
• Characterisation
• Questions
2
• Metadata
• Markup
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)
3
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)
4
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"
5
"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>
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>
6
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:
8
– 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
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:
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Need DTD
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
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See <URL: http://www.w3.org/Talks/
1998/04/WWW7-XML/>
XLink, XPointer and XSL
XLink will provide sophisticated
England
hyperlinking missing in HTML:
France
• 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
<commentary xml:link="extended" inline="false">
• Link databases
<locator href="smith2.1" role="Essay"/>
<locator href="jones1.4" role="Rebuttal"/>
XPointer will provide
<locator href="robin3.2" role="Comparison"/>
access to arbitrary
</commentary>
portions of XML resource
XSL stylesheet language will provide extensibility and
transformation facilities (e.g. create a table of contents)
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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/
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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:
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 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
HTTP/NG
HTTP/NG:
• Based on convergence of Internet protocols
• Two W3C Working Groups:
Web Characterisations:
Study Web usage and form requirements
New 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
16
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/>
18
Metadata
Metadata - the missing architectural component from
the initial implementation
of the web
Addressing
URL
Metadata Needs:
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•
•
•
•
•
•
Resource discovery
Content filtering
Authentication
Improved navigation
Multiple format support
Rights management
Transport Data format
HTML
HTTP
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:
–
–
–
–
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cataloging resources
electronic commerce
digital signatures
intellectual property rights
– resource discovery
– intelligent agents
– content rating
– privacy
• See <URL: http://www.w3.org/
Talks/1998/0417-WWW7-RDF>
RDF
RDF Data Model
RDF:
• Based on a formal
data model (direct
label graphs)
• Syntax for
interchange of data
• Schema model
page.html
Cost
Resource
Property
PropName
Cost
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Value
Property
page.html
£0.05
PropObj
InstanceOf
PropertyType
Value
ValidUntil
11-May-98
Cost
£0.05
ValidUntil
11-May-98
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>
24
Browser Support for RDF
Trusted
Mozilla (Netscape's
3rd
source code release) Party
provides support for Metadata
RDF.
Mozilla supports site
maps in RDF, as well
as bookmarks and
history lists
Embedded
See Netscape's or
Metadata
HotWired home page e.g.
sitemaps
for a link to the RDF
file.
Image from http://purl.oclc.org/net/eric/talks/www7/devday/
25
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>
26
Random Thoughts on Software
Development for the Web
Keynote 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 Papers
218 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>
28
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 Information
Structure 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/>
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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>
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
31
Search and Indexing Techniques
http://google.stanford.edu/
The Anatomy of a Large
Scale Hypertextual Web
Search Engine Brin & Page,
Stanford Univ
• Describes Google, a largescale search engine
developed for research
purposes
• Uses link information
• Use of service and
feedback is encouraged
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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 Issues
More sophisticated deployment techniques can be
adopted to overcome deficiencies in simple model
Original Model
HTML
resource
Web
server
browser
Sophisticated Model
HTML /
XML /
database
resource
Intelligent
Web
server
Intermediaries can provide
functionality not available at client:
• DOI support
• XML support
35 • Format conversion
Web server simply sends
file to client
File contains redundant
information (for old
browsers) plus client
interrogation support
Client
proxy
browser
Server
proxy
HTML Validation service
Example of an intermediary
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
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