WST500: Introduction to Web Science and Technologyislab.kaist.ac.kr/Lecture/wst500_2012_Spring/pdf/wst500_ko.pdf · WST500: Introduction to Web Science and Technology Dept. of Computer

Korea Advanced Institute of Science and Technology

Spring 2012

WST500:

Introduction to Web Science and Technology

Dept. of Computer Science &

Web Science and Technology

In-Young Ko

Web Software Engineering


Today’s Plan

Introduction

Characteristics of Web Applications Product-related Characteristics

User-related Characteristics

Development-related Characteristics

Web Software Engineering Issues Web Application Modeling

Web Services Engineering

Conclusion

Spring 2012 WST 500 Copyright (c) In-Young Ko, KAIST

2


The Origin of the Web

A proposal to build a global hypertext system for CERN

Spring 2012

Tim Berners-Lee,

1989

“Information Management: A Proposal”

www.w3.org/History/1989/proposal.html

WST 500 Copyright (c) In-Young Ko, KAIST

3

http://public.web.cern.ch/public/about/what/what.html


Web Document vs. Web-based SW


4


Web as a Software Platform

Spring 2012

http://www.w3.org/2007/08/sb_gitex/all.htm#(4)


5


The Web: A Platform for Software Engineering

Provides repositories for searching software component services

Provides a medium for deploying software components as services

Supports protocols to access software services

Supports an environment to dynamically compose (assemble or synthesize) software systems

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Web-based Software Environment

Web Services

Customized Applications





6

Characteristics of Web Applications


7


50 Best Websites 2009

1. Flickr 2. California Coastline 3. Delicious 4. Metafilter 5. popurls 6. Twitter 7. Skype 8. Boing Boing 9. Academic Earth 10.OpenTable 11.Google 12.YouTube 13.Wolfram|Alpha 14.Hulu 15.Vimeo 16.Fora TV 17.Craiglook

Spring 2012

17. Shop Goodwill 18. Amazon 19. Kayak 20. Netflix 21. Etsy 22. PropertyShark.com 23. Redfin 24. Wikipedia 25. Internet Archive 26. Kiva 27. ConsumerSearch 28. Metacritic 29. Pollster 30. Facebook 32. Pandora and Last.fm 33. Musicovery 34. Spotify

35. Supercook 36. Yelp 37. Visuwords 38. CouchSurfing 39. BabyNameWizard.co

m's NameVoyager 40. Mint 41. TripIt 42. Aardvark 43. drop.io 44. Issuu 45. Photosynth 46. OMGPOP 47. WorldWideTelescope 48. Fonolo 49. Get High Now 50. Know Your Meme

http://www.time.com/time/specials/packages/completelist/0,29569,1918031,00.html


8

http://www.time.com/


Categories of Web Applications

Spring 2012

[Kap06]


9


Web Applications

Web is evolving into an application medium

Web applications: “full-fledged, complex software systems providing interactive, data intensive, and customizable services” [Kap06]

Characteristics of Web applications Document centricity Non-linear hypertext Spontaneity of users Constantly changing user requirements Network centricity Multidisciplanary Multi-culturality …

Spring 2012

[Kap06]


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Content, Hypertext and Presentation


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Product-related Characteristics

Content Document-centric character and multimediality usability

requirements, dynamic content generation and updates

Quality demands high frequency of updates, high quality requirements

Hypertext Non-linearity of hypertext contents modeling, usability

requirements

Disorientation and cognitive overload modeling, usability requirements

Presentation Aesthetics

Self-explanation without documentation consistent navigation system or interaction behavior, usability requirements

Spring 2012

[Kap06]


12


Understanding Users’ Needs


13


Supporting Various User Types and Environments


14


User-related Characteristics

Social context: users Spontaneity (types and numbers of users cannot be predicted)

architecture design, performance requirements

Multiculturality internationalization, personalization

Technical context: network and devices Quality of service for varying bandwidth, reliability and stability

of transmission medium adaptation, testing

Multi-platform delivery (heterogeneous devices and browsers) adaptive architecture, testing

Natural context: location and time Globality internationalization, security, privacy, location-

awareness support

Availability (instant delivery mechanism) stability, time-aware services

Spring 2012

[Kap06]


15


Multi-disciplinary Development


16


Community Development


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Development-related Characteristics (1/2)

The development team

Multidisciplinarity (print publishing + software development + marketing + computing + art +…) a team of designers, domain experts, and IT experts

Community development component & service standards, collaborative development

Technical infrastructure

Inhomogeniety (Web applications depend on two separate external components: server and browser) inter-operation

Immaturity (caused by time-to-market pressure) record keeping of development knowledge

Spring 2012

[Kap06]


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Development-related Characteristics (2/2)

Process

Flexibility (impossible to adhere to a rigid, predefined project plan)

Parallelism (subgroup development, parallel running of development phases)

Integration

Internal integration (integration with legacy systems)

External integration (integration of content and services of external Web applications) information integration, multi-tiered architecture design

Spring 2012

[Kap06]


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Evolution

Continuous change

Constant change of requirements and conditions

Competitive pressure

Need shorter product lifecycles and short development cycles

Fast pace

Short lifespan and frequent updates

Require permanent maintenance

Spring 2012

[Kap06]


20

Web Software Engineering Issues

Spring 2012

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Web Software Engineering

“Web Engineering is the application of systematic and quantifiable approaches (concepts, methods, techniques, tools) to cost-effective requirements analysis, design, implementation, testing, operation, and maintenance of high-quality Web applications, and the scientific discipline concerned with the study of these approaches.” [Desphande et al.]

Software Engineering = Engineering + Computer Science & Mathematical Principles

Web Software Engineering = Software Engineering + Special Concerns about the Characteristics of Web applications


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Web Software Engineering Issues

Web Application Modeling

Web Services Engineering Service-Oriented Architecture (SOA)

Dynamic Service Composition and Adaptation

End User Mashups

Web Software Reliability

Web Application Usability

Other Web Applications Semantic Web Applications

Social Web Applications

Linked Data Applications


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Requirements of Application Modeling

Spring 2012

‘What’ and ‘how’ of

an application

[Kap06]

Traditional Applications

Web Applications


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Web Application Modeling (1/2)

Clear separation of the three levels

Reduce complexity in providing different hypertext structures and presentations for different types of users based on the same information structure

Separation of concerns

Provide different access paths to the same content

Hypertext modeling needs to be done based on recurring navigation patterns

Consistent presentation structure

Spring 2012

[Kap06]


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Web Application Modeling (2/2)

Aspects Static (less behavior) vs. dynamic (interactive) Web

applications

Phases Information-driven approach – starting with content

modeling

Presentation-driven approach – starting with modeling of presentation aspects

Customization Adapt Web applications based on context, e.g., users’

preferences, device characteristics, or bandwidth restrictions

Spring 2012

[Kap06]


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Web Application Modeling Methods

Entity-Relationship (ER) Model

Data engineering model

For representing structural aspects (entities, groupings, and relationships)

e.g., WebML, RMM, Hera

Unified Modeling Language (UML)

Object-oriented modeling language

Structural diagrams – class, component, composite structure, deployment diagrams, etc.

Behavioral diagrams – use case, state, activity, etc.

e.g., UWE, OOHDM, OO-H

Spring 2012

[Kap06]


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Connections & Services

Spring 2012

www.say-service.com/approach.php...ang%3Den

http://www.augmented.org/pix/arconcept.jpg

http://static.howstuffworks.com/gif/wifi-phone-3.jpg

http://public.cenriqueortiz.com/images/feature-smart-phone.png

http://www.wifigator.com/b-img/publicsafety_diag.jpg

http://www.blogcdn.com/www.tuaw.com

/media/2007/06/iphone_email.png


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Layers in Service Engineering

Spring 2012

Connections

WiFi Blutooth WiMax LAN Various types

of connections

in everywhere

HSDPA

…

Devices

Many networked

devices

surrounding us

… Services and Information

Various services and

information that can

be accessed in

anywhere

…

Customized

applications

Applications

• Multi-dimensional Information Management

• Mobile Life-Navigation Systems

• Social Community Recommendations …


29

http://www.google.co.kr/imgres?imgurl=http://gigaom.files.wordpress.com/2009/02/facebook-logo.jpg&imgrefurl=http://gigaom.com/2009/09/09/when-it-comes-to-facebook-mobile-carriers-want-less-data/&h=301&w=800&sz=79&tbnid=zJxMgbsojbq3jM:&tbnh=54&tbnw=143&prev=/images?q=facebook&hl=ko&usg=__ukSjp5UrGRWK0yoCQxXlDpdOqEI=&ei=SJu-So-AKo2o8Aa70_ipAQ&sa=X&oi=image_result&resnum=23&ct=image


New Challenges

Small Scale vs. Large Scale

Short Term vs. Long Term

Instantaneous vs. Diachronic

Individual vs. Social

Planned vs. Spontaneous

Proactive (off-line) vs. Reactive (on-the-fly) service

compositions

Developer made vs. User made


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Two Perspectives

User-centricity

On-demand application composition (mash-up)

Connecting users’ (high-level) needs to the services, devices, and connections

Dynamism

Making applications work with different services and devices under different connection environments

Memorizing and reusing useful applications for certain situations and environments


31


User-centric Computing Paradigms

Task-driven Computing [Zhenyu Wang & David Garlan]

“Users can interact with the system in terms of high-level tasks instead of individual services or applications”

Activity-based Computing [www.activitybasedcomputing.com]

Provide activity-centered collection of applications, services, and data

Activity adaptation to the available resources on heterogeneous computing devices

Goal-driven Computing [Kangkang Zhang, Qingzhong Li, Qi Sui]

Enable users to achieve their high-level task goals

Improve the flexibility of service cooperation and composition


32


Layers

Composition Layer

• Task-driven service selection and composition

• Dynamic service reconfiguration and optimization

Distributed Service Repositories

Service Mash-ups

Client-application Repositories

Service Layer

• Distributed context and service information management

• Seamless service handover

• Diachronic service management

Task Layer

• Task authoring & feedback

• Dynamic download and installation of client applications

• Social-network-based group interactions


33


End-user Mashups (1/2)

Mashup reuse and versioning

Mashup testing and dependability

Visual composition modeling

End-user programming paradigms

Spring 2012

Yahoo! Pipes


34


End-user Mashups (2/2)

Spring 2012

Lighting Service

Display Service

Room Climate

Control Service

Storyboard UI


35


Dynamic Service Composition

Spring 2012

User Requirement

Changes

Exceptional

Situations

Environmental

Changes

Applications

Context Awareness

Support

Context-sensitive

Component Brokering

Dynamic Application

Composition and

Reconfiguration


36

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1186773&Sku=M401-1006

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1216638&Sku=H24-FA362A

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1227329&Sku=M240-1002


Conclusion – Internet of Services


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References

Gerti Kappel, Elke Michlmayr, Birgit Pröll, Siegfried Reich, Werner Retschitzegge, Web Engineering - Old wine in new bottles?, International Conference on Web Engineering (ICWE), Munich 2004, LNCS 3240, pp. 6-12.

Wieland Schwinger, Koch Nora, Modeling Web Applications, In Gerti Kappel (eds.), Web Engineering – The Discipline of Systematic Development of Web Applications, John Wiley & Sons, 2006.

M. Matera, F. Rizzo, G. Toffetti Carughi. Web Usability: Principles and Evaluation Methods. In E. Mendes, N. Mosley (eds.), Web Engineering. Springer Verlag, ISBN: 3-540-28196-7, 2006.

Michael N. Huhns, Munindar P. Singh, Service-Oriented Computing: Key Concepts and Principles, IEEE Internet Computing, January/February 2005.

Daniel, F.; Matera, M.; Weiss, M.; , Next in Mashup Development: User-Created Apps on the Web, IT Professional, vol.13, no.5, pp.22-29, Sept.-Oct. 2011.

Margaret Burnett, Curtis Cook, Gregg Rothermel, End-User Software Engineering, Communications of the ACM, Vol. 47, No. 9, pp. 53-58, September 2004.

Spring 2012

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Questions?


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Documents

WST500: Introduction to Web Science and Technologyislab.kaist.ac.kr/Lecture/wst500_2012_Spring/pdf/wst500_ko.pdf · WST500: Introduction to Web Science and Technology Dept. of Computer