Transcript Powerpoint 97/2000 Format

Future Technologies:
Deployment Issues
Brian Kelly
UK Web Focus
UKOLN
University of Bath
Email Address
[email protected]
URL
http://www.ukoln.ac.uk/
UKOLN is funded by the Library and Information Commission, 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
• Barriers to Deployment
• Revisiting Data Formats:
• HTML and XHTML
• CSS
• Where Are We: Four Case
Studies
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Entry Points
Search Engines
404 error messages
Web Gateways
Metadata
Browser Issues
Content Management Systems
Deployment Issues
Conclusions
Aims of Talk
• To consider barriers to
deployment of new
technologies
• To address
implementation models
for new technologies
• To look at case studies
in a number of areas
Barriers to Deployment
What barriers can you think of?
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Your Concerns
I know that CSS, XML, HTTP/1.1, RDF, etc.
are good ideas.
But:
• I don't want to be at the leading edge
• I want to be at the leading edge and have
to convince by boss
• I want to stick with the Web circa 1996
• We've only got Netscape 3 browsers
• You can't do much in FrontPage 97
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The Scale of the Problem
Note: Analysis aborted after 15,315 pages
Off-site links not checked
Analysis files over 160Mb
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HTML  XHMTL
XHTML:
• Future-proofs your HTML
• Has beneficial side-effects:
<p>closed papa</p> - CSS rendered correctly
• Example of why you need valid HTML resources
Deployment:
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•
•
Much XHTML support provided by authoring tools
<br / > is a problem
Problem with vi, Notepad, etc.
Tidy utility for retrospective conversion – see
<http://www.w3.org/People/Raggett/tidy/>
Caveats:
• Still a Proposed Recommendation
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HTML  CSS
CSS:
• Preferred way of defining document appearance
Problems:
• Netscape has very poor support of CSS
• Netscape and IE have incomplete support
Deployment:
• Should be used today
• For manually-created CSS consult list of safe CSS
at <http://www.webreview.com/guides/style/>
• Modern authoring tools may produce safe CSS
• User-agent negotiation may be used
• See also Core Style Sheets at
<http://www.w3.org/StyleSheets/Core/>
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Case Studies
"It can be dangerous and expensive to be
at the leading edge. There are also dangers
in being left behind"
How is the UK HE community addressing:
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Institutional Home Page
Searching institutional web service
404 error messages
Web gateways
Case Study 1: Home Page
View a tour of Yorkshire University home pages at
<http://www.ukoln.ac.uk/web-focus/events/
seminars/brad-web2000/web-tour/>.
What do you notice? How does Bradford compare?
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Case Study 2: Searching
View a tour of Yorkshire University search interfaces at
<http://www.ukoln.ac.uk/web-focus/events/
seminars/brad-web2000/web-tour-search/>.
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Case Study 3: Gateways
View a tour of Yorkshire University web gateways at
<http://www.ukoln.ac.uk/web-focus/events/
seminars/brad-web2000/web-tour-gateway/>.
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Case Study 4: Home Page
View a tour of Yorkshire University home pages at
<http://www.ukoln.ac.uk/web-focus/events/
seminars/brad-web2000/web-tour-404/>.
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Workshop
"Institutional Web Management: The Next Steps"
workshop:
• Held at Goldsmith College on 7-9 Sept 99
• Third in series of annual events aimed at
institutional web managers
• Key themes:
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–
–
–
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Resourcing (John Slater),
Personalisation (Joe Passmore, Ulster)
E-Business (David Christmas, OU)
Content Management (Stephen Emmott, KCL and others)
Multimedia (Greg Newton-Ingham [UEA] and Michael
Wilson, RAL)
• See workshop report (and links to materials)
at <http://www.ariadne.ac.uk/issue21/
web-focus/>
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Metadata
Metadata: Structured information for use by applications
HTML: Unstructured information for viewing by people
Metadata is growing in importance:
• Resource discovery
• Web site administration
• B2B (business to business) applications
Dublin Core:
• Standard for resource discovery metadata
• Not yet supported by search engine vendors
• Growing importance in specific communities
(e.g. UK HE for national searching, HE Mall?)
• Metadata management an issue
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Metadata Example
The Exploit Interactive web magazine uses Dublin
Core metadata to provide enhanced searching locally.
The metadata can also be used by third party
applications
http://www.exploit-lib.org/
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You are unlikely to be
motivated to use
metadata (for
example) unless
there is are clear
benefits.
This enhanced
search service will
encourage
information providers
to provide the
metadata
Metadata Example (2)
Exploit Interactive uses ASP to manage server-side
includes. As well as including standard navigational
aids, the SSIs transform the metadata
article.asp
Title="foo"
Description ="xxx"
..
<! include dc-metadata.ssi)>
<! include article.htm>
..
<! include footer.ssi)>
dc-metadata.ssi
<meta content="DC.description"
value = "<%=description %>"
<meta content="description"
value = "<%=description %>"
article.htm
Stored in neutral format,
which helps reuse
Storing metadata in neutral format and transforming it will
enable it be transformed into new formats (e.g. RDF)
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Browser Issues
The web was designed to be evolvable and backwards
compatible
Unfortunately this isn't the case, due to:
• Proprietary extensions which do not coexist with
standards
• Authoring tools which make it easy to propagate
proprietary extensions and poor markup (cf. MS
Word)
• Pace of web development
• Browser bugs
• Difficulties in getting rid of (flawed) old browsers
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Browser Issues
Issues:
• Should organisations adopt a browser management
policy (cf. operating systems, word processors,
etc.)?
• Which browser / browser version to choose?
• What about specialist browsers (PDAs, Lynx,
Opera, etc)?
• Need for browser management kit to minimise
maintenance
Talk by Brett Burridge on this topic. See
<http://www.ukoln.ac.uk/web-focus/events/
workshops/webmaster-sep1999/materials/
browser-management/>
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Browser Issues
Even with a browser policy, you still have to consider
support for other browsers (esp. for public web site):
Client-Side Browser sniffing:
• Javascript in all HTML pages
• Maintenance problem
Server-Side Browser sniffing:
• In server-side language (e.g. ASP / PHP/FI)
• Could be used to deliver safe CSS (e.g. see
<www.disinhe.ac.uk> in Netscape and IE)
Protocol Developments:
• Support for PDAs, WebTVs, etc
• Transparent Content Negotiation and CC/PP
• One for the future
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Content Management Systems
Approaches such as external CSS files, SSI for
managing reusable fragment, etc. are useful
But:
• Still a file-oriented view
• Help manage a web site aimed at human use
• May be difficult to manage server and client-side
code
Content management systems
• May have a database or object-oriented view
• May help manage a web site which can be repurposed
• Likely to have backend XML data store
and use XSL to transform to HTML / CSS
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Deployment Issues
More sophisticated deployment techniques can be
adopted to overcome deficiencies in simple model
Original Model
Web
server
HTML
resource
browser
Sophisticated Model
Backend
processing
HTML /
XML /
database
resource
Intelligent
Web
server
Is it time to move on from using authoring
tools to manage files to content
managements systems which manage
objects and enable resources to be repurposed?
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Web server simply sends
file to client
File contains redundant
information (for old
browsers) plus client
interrogation support
Client
proxy
browser
Server
proxy
Cultural Issues
University "culture" may influence directions of web
developments
How did you address need for Help Desk tracking
software:
• Make decisions internally or liase with other
institutions?
• Buy an off-the-shelf shrink-wrapped package
• Write an MS Access database application
• Take a C compiler and Linux server
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What Next For Bradford?
Conservative
Stay as you are.
If so, make this a
deliberate
approach, and be
aware of strength
and weaknesses
Change (1)
Introduce new
innovations.
Make use of offthe-shelf solutions
What should
you do next?
A Fourth Way
Are there alternative approaches?
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Change (2)
Introduce new
innovations.
Make use of open
source solutions
and home-grown
approaches
Collaboration
You can't do it all on your own
Events:
Mailing lists:
web-support
website-info-mgt
…
Working
Together
Annual Institutional
Web Management
workshops
…
Regional Events:
Yorkshire (and
beyond?) events?
JISC:
JTAP projects and
reports
JISC reports
Other Institutions:
Relevant web resources
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Conclusions
To conclude:
• Standards are important
• Implementation requires much thought
• More sophisticated architectures can help
avoid human errors in managing web sites
• You will need to decide on an open-sources
vs. shrink-wrapped solution
• You can't to it all on your own
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