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IMS5401Web-based Systems Development

Topic 4: Web-based systems development: Putting it all in context and repeating myself

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Agenda

• The web and web-based systems in context

• Where has the web got to and where is it going?

• What should you know?• The Exam

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1. The web and web-based systems in context

• The web is still a relatively new technology• To understand attitudes to the web and its

use, you must understand the context within which it has developed

• YOUR attitude to the web will be affected by the context in which you have used it

• Following are some important contextual issues

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Context: information and its uses

• Managing information through history:• Sumerian, Egyptian and Inca accounting systems

• The telegraph and telephone

• The Railway Clearing House

• To what extent do patterns repeat or change?• A hierarchy of purposes:

• Top level (most general) - recording, storing, retrieving, manipulating, displaying, communicating

• Middle levels - Finance, personnel, inventory management, sales, GIS, DSS, ERP, e-mail, etc

• Bottom level (most specific) - Monash’s finance, personnel, etc systems, Allocate+, Syllabus+, etc

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Context: information technology

• Tools with the same sort of hierarchy of capabilities:• Top level (most general) - recording, storing,

retrieving, manipulating, displaying, communicating

• Middle levels - families of software packages and hardware devices developed as tools for different tasks - database, spreadsheet, printers, etc

• Bottom level (most specific) - software and hardware packages customised and installed at a particular site

• Note the theoretical limits to the flexibility of the technology …

• …Contrast with the practical limits!

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Context: information perspectives

• Technology-based - making technology work• Information-based - managing records; access

and availability• Information-based - managing information

collections; classification and searching• User-based - understanding what the user

wants• Systems-based - integrating related elements• Business-based - linking business information

needs and functions

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Context: about system development

• Fitting the development process to the development task • What is the nature of what is being developed?

• What sort of activities are needed?

• What sort of techniques have to be used?

• What sort of project management is required?

• Traditions in development process• Engineering/Architectural/Design/etc

• Finding the right blend

• Standards and creativity: recipes vs ad hoc methods

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Context for understanding the web

Applications•Information purpose

•Specific info needs

Technologies•Hardware tools

•Software tools

Development processes•Tasks/activities

•Techniques

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Context for information professionals

• Matching technological capability to application (information need) and development process

• Some dangers to be avoided:• Failure to understand: the technology/the application/the

development process

• Choosing the wrong mix of technology and application: good technology/wrong application; good application/wrong technology (over-ambitious or under-ambitious)

• Choosing the wrong development process – for the need or for the technology

• Many many examples in history of IS and IT!• Our role: sit in the middle and help get it right

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2. Where has the web got to and where is it going?

• Still a technology in its relative infancy• An evolving technology, not a purpose-

built technology• Only experience will prove what works• Individual applications are in various

stages of their development/evolution

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Perspectives of the web

• The “Brave New World” view (the web changes everything)

• “The Emperor has No Clothes” view (the web changes nothing)

• The Specialist technology application view (the web changes some things for some applications)

• The Foundational Infrastructure view (the web provides a new basis for everything)

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An information-based view: the web and the IT sausage

• Basic IT functionality• Data input• Data storage• Data processing• Data output and display• Data communication

• However the web changes things technologically, it does not change the fundamental information issues

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The web as fine cuisine

• The web offers information sharing of a kind we have never known before

• The web offers potential access to systems on a scale we have never seen before

• The web enables new business models which have transformed some industries and may soon transform others

• The web’s capacities have been only partly used; improving technologies and improved understanding of how to use it will expand its uses still further

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System development for the web

• If Information Technology is the sausage, systems development is the cooking

• Cooking techniques - standard and specialised: roast lamb, curries, fried rice, samosas, pastry cooking, pavlovas, sauces, spices, etc etc

• Knowing how to cook anything? … everything??

• Being a good chef

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3. What should you know?

• Everyone in the information business must know about web technologies and development

• There are too many aspects to the web for you to have the time to keep track of them all

• Your must maintain a basis competence and understanding of the key web elements

• Your job/career interests will determine which bits you need to know better

• Knowing what you need to know versus knowing everything

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What should you know …… about the inter-relationship of web technologies?

THE WEB

Connecting computers

Digital representationof documents

Formatting documents for:(a) display(b) searching

Linkingdocuments

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What should you know …… about web/internet infrastructure?

• The simple picture of what they were designed to do; de-centralised network connectivity and its implications

• Basic features and terminology of the infrastructure:• Domain names and IP addresses• Web pages, servers and URLs • TCP/IP protocol for sending and receiving

• Implications for web developers

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What should you know …… about hypertext?

• What it is – the basic principle of document linking through the http protocol

• Why it is useful – what purposes hypertext linking can meet

• What problems it creates – difficulties of hypertext structures

• Implications for web developers

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What should you know …… about using multimedia?

• The importance and use of multimedia• How are different media types represented in

digital form, and what are the implications for file sizes and file formats?

• How can you reduce file sizes and minimise the number of file formats? What costs do you pay?

• How important is multimedia to the user and what is the trade-off for page transmission?

• Implications for web developers

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What should you know …… about data transmission?

• The central importance of data transmission to the internet/web

• Standard terminology: bandwidth, broadband, proxy servers, cache, bps

• The transmission media and their key characteristics (very broad)

• Transmission speeds (very broad)• Other factors in data transmission• Implications for web developers

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What should you know …… about mark-up languages?

• The document formatting problem and the basic principles of a mark-up language

• Mark-up for presentation, for style, for content, etc

• The general outline of the development of web mark-up: from HTML to XHTML and XML

• Browsers and plug-ins for document display• Implications for web developers

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What should you know …… about metadata and web searching?

• Formatting documents for cataloguing and searching: metadata and its importance

• How do search engines work?• How much can we rely on search engines for

making web content findable?• What does this mean for finding things on the

web?

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What should you know …… about the semantic web?

• Building meaning into document content: metadata and the semantic web

• Why do we need it - data-based vs page-based information

• The basic technologies of the semantic web (very broad level only)

• Problems in making it work• Implications for future web usage

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What should you know …… about web interactivity?

• How the structure of the web affects interactivity

• Client-side vs server side interactivity• Terminology: client-server, scripting languages,

Javascript, CGI, cookies • Faking interactivity with cookies• Implications for web developers

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What should you know …… about web services?

• What is the basic aim behind web services?• What are the key technologies behind it?• Issues, problems and opportunities for

organisations• Implications for future web usage?

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The context for development process

Web Application (Purpose)

Development Process

Web Technology

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What should you know …… about the web development process?

• Unique features/capabilities of web systems which affect web development

• Differences and similarities with traditional IS development processes

• Their implications for web development process

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What should you know …… about web content and layout?

• Issues in content and layout design: the nature of the design problem for web developers

• Web page usability: user characteristics and their implications for web content

• Types of web content: technology and usage issues affecting choice of content

• Page layout and graphic design – key page elements and issues for their design

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What should you know …… about web site architecture and navigation?

• Organisation and classification systems -Why do they matter?

• Organisation structures - their strengths and weaknesses

• Labelling • Navigation methods and issues in navigation

design• Approaches to identifying user needs (outline

only)

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What should you know …… about web interaction?

• Elements of interaction design• What might users want from a web site?• What sorts of audiences might a web site have

to be designed for?• How do the audience characteristics and needs

affect site design?• Compromise in interaction design

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What should you know …… about designing for maintainability?

• Maintenance issues: site growth and evolution• Site evaluation and performance• Content maintenance and content management

systems• How should post-implementation issues affect

design?

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What should you know …… about the role of info professionals in web design?

• Key influences on development process• Comparing web development with traditional IS

development • New skills and capabilities needed in web

development

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4. What should you know …… about the Exam?

• Previous exams - the rationale behind them and their usefulness as exam preparation

• This year’s paper - structure and style• Specific web technologies and techniques • Applying web technologies and development

techniques to an information problem• The web as an evolving technology