Download - 1 Advances In Web Technologies Brian Kelly UK Web Focus UKOLN University of Bath [email protected]
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Advances In Web Technologies
Brian Kelly
UK Web Focus
UKOLN
University of Bath
http://www.ukoln.ac.uk/
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Contents• About UK Web Focus• End user developments:
• browsing• searching
• Developments for information providers• document management• metadata• structured documentation
• Technologies• HTML• HTTP• Java
• Will it Take Off In Our Community?
Aim of this talk:• To outline major developments
on the web• To explain why they are important• To identify possible barriers to
their use
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UK Web FocusUK Web Focus:
• National web coordination post for UK HE community
• Based at UKOLN, University of Bath
• Responsibilities include:– Technology watch– Information dissemination in variety of ways:
– Workshops (national, regional)– Presentations at conferences and seminars– Online
– Coordination activities– Representing JISC on W3C
• Brian Kelly appointed on 1st November 1996– Involved with web since January 1993– Previously worked at University of Newcastle, Leeds,
Liverpool, and Loughborough
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Web VisualisationVisualisation of a web site to aid end user navigation
Why: To make navigation easier for end usersTo provide tailorable views (e.g. only show "personal home pages")
Barriers: Lack of standards. Proprietary, licensed software.
How: Web Collections
Familiarisation: MAPA, NetObjects Fusion See also WebCutter at
http://www6.nttlabs.com/HyperNews/get/PAPER40.html
See also WebCutter at http://www6.nttlabs.com/HyperNews/get/PAPER40.html
http://www.dynamicdiagrams.com/
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Light-weight Browsers
Light-weight browsers such as Opera and Lynx are available
Why: To support low spec PCs (e.g. 386 SX with 8MB and Win 3.1)
Barriers: Costs ($10 for 100-500 copies), use of proprietary HTML
How: Opera, Lynx, Bobcat
Familiarisation: Free evaluation
http://opera.nta.no/http://www.operasoftware.com/
http://lynx.browser.org/http://www.fdisk.com/doslynx/
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Better Searching (1)Why: Time wasted in
searching
Barriers: Lack of metadata standards. Lack of tools
How: Dublin Core
Familiarisation: Read UKOLN resources at http://www.ukoln.ac.uk/metadata/
Take part in pilot
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Better Searching (2)
Application of heuristic techniques in searching
Why: Time wasted in searching
Barriers: Lack of organisational guidelines
How: Heuristics.Consistency in URLs across institution
Familiarisation: Ahoy!
http://ahoy.cs.washington.edu:6060/
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A Manageable Web (1)Use of metadata for site management
Why: Site metadata on authoring tools, authoring methods, document types, ..
Barriers: Lack of standards
How: Dublin Core, PICS, XML,...
Familiarisation: UKOLN metadata work, UCISA-TLIG work
Metadata to assist with following requests:
• Find all pages created using Internet Assistant v1
• Find all pages which use Jscript
• Find pages where author = {find author from departed-staff}
Metadata to assist with following requests:
• Find all pages created using Internet Assistant v1
• Find all pages which use Jscript
• Find pages where author = {find author from departed-staff}
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Development of a Metadata Architecture
Metadata - the missing architectural component from the initial implementation of the web
Metadata
PICS, TCN,
MCF, DSig,
DC,...
AddressingURL
Data formatHTML
TransportHTTP
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Metadata Components
PICS, Digital Signatures, Transparent Content Negotiation, resource discovery, website administration are all related to metadata
ExampleImagine you make your University prospectus available on the web.
What metadata may be required?
Use Of MetadataPICS Resource accessible to users in
Middle East, which ban unrated sitesDSig Description of course is a legally
binding agreementTCN Resource can transparently be
accessed in HTML or PDF formatWeb Collections
Print resource as single documentResource Discovery
Search for Bath prospectus finds itWebsite Administration
Use of review-by to find out-of-date material
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A Manageable Web (2)
Use of server side management techniques
Why: Single copy to minimise maintenance
Barriers: Performance, cost of software, Unix
How: Server side includes,
Familiarisation: MS Active Server Pages, Netscape SuiteTools, PHP/FI, ...
<If useragent=netscape1.1 thenelse if useragent= …>
<P>This resource is copyright ...
Adding code / text to static HTML resource:
• complex• difficult to maintain
Adding code / text to static HTML resource:
• complex• difficult to maintain
<#If useragent=netscape1.1 thenelse if useragent= …>
<#include copyright-1.txt>
Server side management tools:
• HTML resource clean• easier to maintain
Server side management tools:
• HTML resource clean• easier to maintain
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<SCRIPT LANGUAGE="JavaScript"><!-- Hide this from JavaScript-challenged browsersvar FirstSlide = 1;var LastSlide = 17; var CurrentSlide = FirstSlide;var ImageWidth = 708 - 8;var ImageHeight = 520; var CurImageWidth = ImageWidth; var CurImageHeight = ImageHeight;/* This function concerts numbers to strings */function CvtNtoS(iNum){return ("" + iNum);}/* This function prefixes strings with the correct # of 0's */function ZeroFill(iNum, iDigits){ var sNum = CvtNtoS(iNum); while (sNum.length < iDigits) sNum = "0" + sNum; return sNum;}/* this function handles the setting the navigation buttons. The name of navigation control is used here so change it if it is renamed */function ItemClicked(iIndex, iNoteOnly){var sIndex = ZeroFill(iIndex, 3); var sNoteHref = "note" + sIndex + ".htm"; var sSlideImage = "img" + sIndex + ".htm"; if (!iNoteOnly) // not active X, update image and nav btns frames["SlideImage"].location.href = sSlideImage; frames["Notes"].location.href = sNoteHref; CurrentSlide = iIndex;}
<STRONG>Demise of Tags</STRONG>
Demise of text editors for authoringWhy: HTML will be too
complex
Barriers: Inertia. Too many tools!
How: Recommendations on authoring tools
Familiarisation: Front Page, Netobjects Fusion, ...
<HTML><BODY ><A HREF="JavaScript:parent.ItemClicked(1, 0)"> An Introduction to Metadata </A><BR><A HREF="JavaScript:parent.ItemClicked(2, 0)"> UK Web Focus </A><BR><A HREF="JavaScript:parent.ItemClicked(3, 0)"> Early Days of the Web (1) </A><br>
HTML><BODY ><base target="_top"><A HREF="JavaScript:parent.OutlineExpand(0)"><IMG SRC="collapse.gif" BORDER=0 ALT="Collapse"></A><A HREF="JavaScript:parent.OutlineExpand(1)"><IMG SRC="expand.gif" BORDER=0 ALT="Expand"></A>
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HTML DevelopmentsEnd user control over layout, better printing, ...
Why: Increased functionality
Barriers: Lack of standards
How: CSS, HTML 4.0 (Cougar)
Familiarisation: IE 4, Netscape 4, HTML 4.0 proposal, CSS 2 proposal
HTML 4.0 and Related Work
• Forms:Improved forms
• Printing:Better control over printing
• Layout:Absolute positioning of HTML elements, layering, etc.
• Scripting:Standard mechanisms for scripting.
• Document Object Model (DOM): APIs (application program interface) for HTML/CSS elements. Provides a programming interface for HTML (hooks for Javascript, etc.)
HTML 4.0 and Related Work
• Forms:Improved forms
• Printing:Better control over printing
• Layout:Absolute positioning of HTML elements, layering, etc.
• Scripting:Standard mechanisms for scripting.
• Document Object Model (DOM): APIs (application program interface) for HTML/CSS elements. Provides a programming interface for HTML (hooks for Javascript, etc.)
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The SGML / HTML philosophy is to use HTML to define the document structure
Netscape / Microsoft wars have broken this
Companies are now supporting CSS:
• Ease of maintenance
• Richer functionality (e.g. filter effects as in Powerpoint)
• Network friendly
• Accessibility
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Increasing Use Of JavaExpect to see increasing use of Java:
Why: Provide extra functionality on client; Minimise support load for desktop applications
Barriers: Performance concerns (real and imaginary - cf XMosaic)
How: Standard web browser
Familiarisation: http://www.gamelan.com/
Z39.50 clients are being developed using Java
Z39.50 clients are being developed using Java
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An Accessible WebWeb resources accessible to people with disabilities
Why: Equality. Spinoffs for "temporarily able-bodied persons"
Barriers: Lack of standards, lack of awareness, misuse of HTML
How: WAI, Institutional policies
Familiarisation: WAI pages
Technologies
• Style sheets: control over appearance needed by designers, but with end user ability to change appearance (not achievable with images)
• Aural style sheets: e.g. <STRONG> rendered as LOUD voice, or pause before phrase, <DT>, <DD> rendered using male / female voices, columns in tables using left and right stereo channels
Technologies
• Style sheets: control over appearance needed by designers, but with end user ability to change appearance (not achievable with images)
• Aural style sheets: e.g. <STRONG> rendered as LOUD voice, or pause before phrase, <DT>, <DD> rendered using male / female voices, columns in tables using left and right stereo channels
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A Customisable Web
End user choice of preferred formats (HTML or PDF, GIF or PNG), features (frames or tables), languages, etc.
Why: Choice for the end user, deployment of new features
Barriers: Lack of standards, misuse of HTML
How: TCN, Cookies
Familiarisation: http://tips.iworld.com/
Replace this with use of cookies or transparent content negotiation
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Maths
Mathematical formulae on the web.
Why: Needed by scientists, images of formulae are slow and have no semantics
Barriers: Lack of standards
How: MML, XML, Java, ActiveX
Familiarisation: http://www.w3.org/MarkUp/Math/
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A Quicker Web
More effective use of scarce bandwidthWhy: The web is too slow!
Barriers: Limitations of protocols (HTML, HTTP)
How: Caching, HTTP/1.1, HTTP/NG, Education, Charging!
Familiarisation: Monitoring web pages, Internet magazines, attending workshops
Technologies
• Caching: Essential!
• HTTP/1.1:New protocol is more cache-aware, and avoids problems (e.g. stale information) which have occurred in the past
• HTTP/NG:Proposal for new protocol
• Style sheets:Avoids need for large images for design effects
• Scripting Languages / Java:Exploit processing power at client
Technologies
• Caching: Essential!
• HTTP/1.1:New protocol is more cache-aware, and avoids problems (e.g. stale information) which have occurred in the past
• HTTP/NG:Proposal for new protocol
• Style sheets:Avoids need for large images for design effects
• Scripting Languages / Java:Exploit processing power at client
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Collaborative ToolsUse of collaborative and conferencing web tools.Why: Provide rich
collaborative tools
Barriers: Lack of locking, notification systems, HTML deficiencies
How: WebDAV work, Cougar
Familiarisation: Amaya, http://union.ncsa.uiuc.edu/HyperNews/get/hypernews.html
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Structured Documentation
Store web resources in a rich structured open master format
Why: To overcome HTML deficiencies
Barriers: Lack of standards. HTML provides little structure
How: XML
Familiarisation: Jumbo browser
See also http://www.textuality.com/xml/
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Richer Hyperlinking
Richer forms of hyperlinking
Why: Increased functionality
Barriers: Lack of standards
How: XML, Javascript
Familiarisation: SoftQuad HiP, http://www.w3.org/XML/
XML-Linking
Multi-way links
Link destination:• Replaces existing
document• Included inline in
document• Displayed in new
window
Resolve link at:• document load• user action
XML-Linking
Multi-way links
Link destination:• Replaces existing
document• Included inline in
document• Displayed in new
window
Resolve link at:• document load• user action
See further instructions
ReferenceTutorial
EnglishFrench
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Push Technologies
Use of push technologies
Why: Push information, teaching and learning services to end users
Barriers: Lack of standards, bandwidth concerns
How: CDF, ...
Familiarisation: PointcastIE 4, Netscape
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Will It Take Off In UK HE?
Barriers to use of new technologies:• Lack of knowledge• Lack of tools• Inertia• Concerns over costs
Solutions:• Education, information, discussion, …• UCISA-SG WebTools group
Commercial pressures• Enthusiasts• Monitoring usage
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UKOLN's WebWatch ProjectWebWatch:
• 1 year post funded by British Library (BLRIC)• Will develop set of robot tools for analysing UK
web resources:– Usage of emerging web technologies, such as HTML 4,
style sheets, Java, metadata, XML, etc.– Usage of file formats (e.g. PDF, Shockwave, …)– Web page profiles (typical nos. of links, images, size, etc)– ...
• Analysis of log files (e.g. user agents)
• Results to be made available to various communities (institutions, national bodies, etc.)
• Feedback on project welcomed
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Conclusions• The web is still developing rapidly• Conformance to standards is important• Institutions will have to continually monitor new
developments (regional workshops, seminars?)• The deployment of new technologies in a timely
manner is a challenge (need for workshops, case studies?)
• There is a danger that the costs will increase when exploiting new developments
• There is a need to monitor developments and to advise the community