Powerpoint 97 Format

advertisement

WWW 7 Trip Report

1

Brian Kelly

UK Web Focus

Email Address

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.

2

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

• Developer's Day

• Keynote on Java

• Papers

• Search engines

• Characterisation

• Question

• Metadata

• Markup

3

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

4

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)

5

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

>

6

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

• Talks available at

<URL: http://www.w3.org/

Conferences/WWW7/W3CTrack.html

>

7

W3C - 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/ >

• See Dave's slides at <URL: http://www.w3.org/Talks/

1998/0416-WWW7-HTML/ >

8

W3C - 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

9

W3C - Maths

MML:

• Math(s) Markup Language

• An XML Application

• W3C Recommendation agreed on 7 April

1998

• Java and ActiveX renderers

• Dave Raggett has authoring tool

(Windows 95 application)

• See <URL: http://www.w3.org/Math/ >

10

W3C - 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/ >

11

W3C - 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 ...

/ >

Use consistent upper/lower case

• and valid :

Need DTD

12

W3C - 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/ >

13

W3C - 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

 Performance benefits!

 Is acting as fire-fighter

 Poor usage counting

 Not sufficiently flexible or extensible

14

W3C - HTTP/NG

HTTP/NG:

• Based on convergence of Internet protocols

• Two W3C Working Groups:

Protocol Design:

Redesign Web as distributed object application

Web Characterisations:

Study Web usage and form requirements

New log format for easier collection and anonymisation

See <URL: http://www.w3.org/Talks/

1998/04/WWW7-HTTP-NG/ >

15

W3C - WAI

WAI (Web Accessibility Initiative):

• Ensures web specs address accessibility issues

Authoring:

• First draft of Page Author Accessibility Checklist and Guidelines available at

<URL: http://www.w3.org/TR/

1998/WD-WAI-PAGEAUTH-0203 >

Software

• User agent / Authoring tools guidelines being produced

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

WWW7-WAI/ >

16

W3C - 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/ >

17

W3C - 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

• See <URL: http://www.w3.org/P3P/ >

18

W3C - 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

– electronic commerce

– resource discovery

– intelligent agents

– digital signatures – content rating

– intellectual property rights – privacy

• See <URL: http://www.w3.org/

Talks/1998/0417-WWW7-RDF >

W3C - RDF

RDF:

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

• Syntax for interchange of data

• Schema model

Resource

PropertyType

Property page.html

RDF Data Model

Cost

Value

£0.05

Cost page.html

PropObj

InstanceOf

PropertyType

PropName

£0.05

Value

ValidUntil

11-May-98

Cost

19

ValidUntil

11-May-98

20

W3C - 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>

21

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.

22

W3C - RDF Conclusion

RDF is a general-purpose framework

RDF provides structured, machineunderstandable metadata for the Web

Metadata vocabularies can be developed without central coordination

RDF Schemas describe the meaning of each property name

Signed RDF is the basis for trust

23

Developer's Day - XML

" So You Want To Be An XML Developer "

Talk by Tim Bray, Textuality

See <URL: http://www.textuality.com/

WWW7/ >

Useful resources:

Annotated Spec at <URL: http://www.xml.com/axmls/axml.html

>

XML FAQ at <URL: http://www.ucc.ie/ xml >

Other pages at <URL: http://www.sil.org/ sgml/xml.html

>

24

Developer's Day - XLink

XLink

• Aims to provide sophisticated hyperlinking functionality missing in HTML

• Formerly known as XML-LINK and XLL

• See <URL: http://sil.org/sgml/xll.html

>

• XLink working draft is stable, though new versions due out

25

Developer's Day - XLink

England

XLink provides:

France

• Links that lead to multiple destinations

• Bidirectional links

• Links with special behaviors:

– Expand-in-place (similar to < IMG SRC >)

– Replace (similar to < A HREF >)

– Create new window

– Link on load (similar to < IMG SRC > or redirect)

– Link on user action

• Link databases

<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>

26

Developer's Day - XPointer

XPointers:

• Based on TEI work

• An XPointer specifies a location in an XML tree structure

• For example:

ID(foo).CHILD(4,SEC).CHILD(1,ABSTRACT) addresses the first XML ABSTRACT element within the fourth SEC element within the element with ID attribute " foo " in a document

• To use:

<A HREF="http://www.xyz.com#ID(foo)

CHILD(4,SEC)CHILD(1,ABSTRACT)">

• Note the working draft is not stable

27

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 is being ported 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. Activator may enable a functioning JVM to be installed (note supports

< OBJECT > tag).

28

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

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

>

29

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

Structure Graph Format: XML Metadata for

Describing Web Site Structure by Liechto et al

Producing site maps based on linking and directory structures

30

Markup

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

This paper 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>This text is displayed as <REVERSE>white text on black</REVERSE>

Information (shortly) at http://www.cs.unibo.it/~fabio/ displet.html

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

32

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

Document life span

25% of servers 85% traffic

About 50 days

33

Web Management

One paper, in Hypertext and Hypermedia session, on web management

WSDM: A User Centred Design Method For Web

Sites by De Troyer et al

This paper proposes a design methodology for web-kiosks.

The paper gives references on methodologies for website design.

34

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

Download