Web Information Systems
Introduction
Prof. Beat Signer
Department of Computer Science
Vrije Universiteit Brussel
http://vub.academia.edu/BeatSigner
2 December 2005

Course Organisation
 Prof. Beat Signer
Vrije Universiteit Brussel
10 F 721
+32 2 629 12 39
bsigner@vub.ac.be
 William Van Woensel
Vrije Universiteit Brussel
10 F 705
+32 2 629 37 54
William.Van.Woensel@vub.ac.be
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 2

Exercises and Assignment
 Course content is deepened in exercise sessions
 Weekly exercise sessions
 starting on September 28
 1E.02, Monday 13:00 – 15:00
 assistant: William Van Woensel
 Additional content may be covered in exercise sessions
 strongly recommended to attend the exercise sessions!
 exam covers content of lectures and exercises
 Assignment handed out in week 6
 individual work that counts 30% for the overall grade
 deadline: December 17
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 3

Exam
 Oral exam in English
 covers content of lectures and exercises
 counts 70% for the overall grade
 Overall grade = oral exam (70%) + assigment (30%)
 Course information (lectures slides, exercises, …)
available on PointCarré
 http://pointcarre.vub.ac.be
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 4

Course Overview
1. Introduction
 history of the Web
2. Web Architectures
 HTTP protocol
 client-side processing
 server-side processing
 multi-tier architectures
3. Markup Languages
 HTML and CSS
 XML, XSLT and XLink
4. Universal Client Access
 WML and VoiceXML
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 5

Course Overview …
5. Web 2.0 Basics
6. Web 2.0 Patterns and Technologies
 SOAs
 mashups
 RIAs
 collaborative tagging
7. Web Application Frameworks
 MVC
 Apache Struts 2, Adobe Flex, OpenLaszlo, Ruby on Rails, …
8. Semantic Web
 RDF, RDFs, OWL, SPARQL, …
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 6

Course Overview …
9. Mobile Web Information Systems
 P2P
 context and proximity
10.Web Search and Retrieval
 Google PageRank
11.Security, Privacy and Trust
12.Future Trends
 internet of things
 cross-media information systems
13.Summary
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 7

"As We May Think" (1945)
... When data of any sort are placed in
storage, they are filed alphabetically
or numerically, and information is
found (when it is) by tracing it down
from subclass to subclass. It can be in
only one place, unless duplicates are
used; one has to have rules as to which
path will locate it, and the rules are Vannevar Bush
cumbersome. Having found one
item, moreover, one has to emerge from
the system and re-enter on a
new path. The human mind does not work
that way. It operates by association.
...
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 8

"As We May Think" (1945) …
... It affords an immediate step,
however, to associative indexing, the
basic idea of which is a
provision whereby any item may be
caused at will to select immediately
and automatically another. This is the
essential feature of the memex. The
process of tying two items together is Vannevar Bush
the important thing. ...
Vannevar Bush, As We May Think,
Atlanic Monthly, July 1945
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 9

"As We May Think" (1945) …
 Bush's article 'As We My Think'
(1945) is often seen as
the “origin" of hypermedia
 Article introduces the Memex
 prototypical hypertext machine
 store and access information
Memex
 follow cross-references (trails)
between pieces of information (microfilms)
 trail blazers are those who find delight in
the task of establishing useful trails
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 10

Scientist of the Future ...
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 11

Memex Movie
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 12

Exercise 1
 Read the paper As We May Think by Vannevar Bush
and try to answer the questions formulated on the
exercise sheet
 Discuss your answers and the paper with your teaching
assistant and classmates during the exercise session
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 13

Hypertext (1965)
 Ted Nelson coined the term hypertext
 Nelson started project Xanadu in 1960
 first hypertext project
 nonsequential writing
 introduced zippered list structure for
referencing/embedding parts of a document
in another document (transclusion) Ted Nelson
 transpointing windows
 bidirectional (bivisible) links
 version and rights management
 Xanalogical structures
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 14

Transpointing Windows Mockup (1972)
[http://www.xanadu.com.au/ted/TN/PARALUNE/paraviz.html]
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 15

Hypertext Editing System, HES (1967)
 Early hypertext system
 developed at Brown University (1967)
by Andries van Dam and his team
 Ted Nelson was a visitor at Brown
University a that time
 Limitations
 unidirectional links
 non-overlapping links
 embedded links
 File Retrieval and Editing System, FRESS (1968)
 follow-up project taking ideas from HES and NLS
 first system introducing 'undo' functionality
 bidirectional links
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 16

The Mother of All Demos (1968)
 Douglas Engelbart and his colleagues
at the Augmentation Research Center
developed the oNLine System (NLS)
 NLS was demonstrated at the Fall
Joint Computer Conference in 1968
 shows first practical use of hypertext
Douglas Engelbart
 remote collaboration (connected computers)
 raster-scan video monitors
 screen windows
 computer mouse
 ...
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 17

NLS Demo
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 18

Aspen Moviemap (1978)
 Early hypermedia system
 developed at MIT by Andrew
Lippman and his team
 hypermedia = extension of
hypertext with other media
types (e.g. images, sounds)
 Virtual tour of Aspen
 pictures taken every 10 feet
while driving through the city
 additional linked media
(e.g. images and sounds)
 Similar concept now used
by Google Street View
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 19

HyperCard (1987)
 One of the early widespread
hypermedia systems
 Released by Apple Computer Inc.
(as part of System Software 6)
 developed by Bill Atkinson
 Information is stored in a series of
cards that are arranged into stacks
 Links can be defined between different cards
 HyperCards may contain text, pictures, audio and video
 HyperTalk programming language is used to execute commands
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 20

ARPANET (1969)
 Advanced Research Projects Agency Network
 created by DARPA (US Department of Defense)
 first operational packet switching network
 first ARPANET link established in November 1969
 ARPANET applications
 Email (1971), Ray Tomlinson
 FTP (1973)
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 21

ARPANET Map (March 1977)
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 22

TCP (1974)
 Transmission control prototcol
 replacement of Network Control
Protocol (NCP)
 'A Protocol for Packet Network
Interconnection'
 by Vint Cerf and Bob Kahn
 Reliable and ordered Vint Cerf Bob Kahn
transmission of byte stream
between two endpoints
 Migration of ARPANET to TCP/IP in 1982
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 23

TCP/IP (1978)
 4 abstraction layers
 each layer offers functionality to the above layer
 separation of concerns
 Application layer
 HTTP, FTP, POP, ...
 Transport layer
 TCP, UDP, ...
 Internet layer
 adressing hosts and packet routing
 IP, ...
 Link layer
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 24

TCP/IP Layers
Application Application
Transport Transport
Internet Internet Internet Internet
Link Link Link Link
Ethernet Satellite, Ethernet
...
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 25

OSI Reference Model (1984)
 Open Systems Intercon- Application
7
nection Reference Model
6
 released by ISO in 1984 Presentation
 dataflow between two
5
computers over network Session
 7 layer model 4
- 3 network layers (1-3) Transport
- 4 host layers (4-7)
3
 aims to simplify network Network
interconnection
2
- standardised interfaces Data Link
- modular and interchangeable
networking components 1
Physical
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 26

OSI Reference Model (1984) ...
 Application layer
 enable acces to network resources
 HTTP, FTP, SMTP, Telnet, ...
 Presentation layer
 translation, compression and encryption
 Session layer
 establish, synchronise and terminate sessions between systems
 Transport layer
 reliable endpoint-to-endpoint message delivery
 TCP, UDP, ...
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 27

OSI Reference Model (1984) ...
 Network layer
 move packets from a source to a destination
 IP, ...
 Data link layer
 divide stream of bits into frames (includes error correction)
 PPP, ...
 Physical layer
 transfer bits over a physical medium (e.g. electrical specifications)
 repeaters, hubs, ...
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 28

World Wide Web (WWW)
 Networked hypertext system
(over ARPANET) to share in-
formation at CERN
 first draft in March 1989
 The Information Mine,
Information Mesh, …?
 Components by end of 1990 Tim Berners-Lee Robert Cailliau
 HyperText Transfer Protocol (HTTP)
 HyperText Markup Language (HTML)
 HTTP server software
 Web browser (WorldWideWeb)
 First public "release" in August 1991
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 29

WordWideWeb Browser (1993)
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 30

WWW and Hypertext
 WWW is mainly a network-enabled version of the
HES hypertext model
 unidirectional links between heterogenous resources
 more than just a digital version of paper documents with links?
 What about all the richer functionality researched by the
hypertext community?
 bidirectional links
 transclusion and external (non-embedded) links
 version management
 …
 Is there something wrong with the WWW?
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 31

Worldwide Number of Hostnames
226'099'841 hostnames
in September 2009
http://news.netcraft.com
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 32

Mobile Web
 HTML as a single markup
language is no longer
enough
 WML, VoiceXML, cHTML, …
 New forms of connectivity
and information exchange
 P2P networks
 …
 New requirements and
functionality
 location-based services The Web becomes accessible
from anywhere at anytime
 …
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 33

Web 2.0
 User becomes an author
and shares information
 tagging
 Wikis
 social networking
 mashups
 ..
 Not a new technology!
 Why did some of these
things not happen earlier?
 limitations of original WWW?
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 34

Semantic Web (Web 3.0)
 Add explicit semantics
to Web resources
 Machine-interpretable
Web
 Use of ontologies
 Potential reasoning over
Web resources
[http://en.wikipedia.org/wiki/File:W3c-semantic-web-layers.svg]
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 35

Internet of Things
 Mark Weiser coined the term Ubiquitous
Computing while working at Xerox PARC
 M. Weiser, The Computer for the 21st Century,
ACM Mobile Computing and Communications
Review, July 1999
 Related terms are Disappearing Computer,
Pervasive Computing or Internet of Things Mark Weiser
 Physical objects with emedded computing functionality
that actively or passively participate in the Web
 mobile phones, RFID-tagged objects, smart pens, …
 Do we have to extend the current Web infrastructure?
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 36

Cross-media Information Systems
 Information moves from
digital to physical space
and vice versa
 e.g. paper-digital integration
 Multimodal interaction
 How should information
be stored and accessed?
 use of web technologies?
 desktop metaphor still EdFest project
appropriate?
 …
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 37

References
 Vannevar Bush, As We May Think, Atlanic Monthly,
July 1945
 http://www.theatlantic.com/doc/194507/bush/
 http://sloan.stanford.edu/MouseSite/Secondary.html
 Videos of the NLS demo
 http://sloan.stanford.edu/mousesite/1968Demo.html
 Aspen Moviemap
 http://www.naimark.net/projects/aspen.html
 Networking Technologies (TCP/IP, …)
 Andrew S. Tanenbaum, Computer Networks, Prentice Hall 2002,
ISBN-13: 978-0130661029
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 38

References …
 Mark Weiser, The Computer for the 21st Century,
ACM Mobile Computing and Communications
Review, July 1999
September 24, 2009 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 39

Next Week
Web Architectures
2 December 2005