Web Programming Methods

What we are going to do… ► Why methods? ► Traditional method examples ► WSDM ► Conclusion

Methods ► Why use one?

Methods ► What it covers  Possibly all stages ► Feasibility ► Analysis ► Design ► Implementation ► Testing  Maybe just some of them ► Just design

Methods ► The one you do…. ► A method must cover front end design, flow and database design (as a minimum)

Where are we with web application design methods?  It’s a relatively new area, most significant work only emerged from 1993 onwards  Very much in the infancy stages  No one solid method has emerged  Few approaches have been rigorously tested  Is this a problem?  We have most methods and technique components we need in existence for a web method, in almost all cases though they have just not been integrated  So, currently we need to work around the issue by forming ‘hybrid’ methods that share and borrow techniques

Non Web Methods ► SSADM? ► SSM? ► UML? ► (Look in Avison / Fitzgerald) ► Suitability for the web?

What is SSADM? ► SSADM (Structured Systems Analysis and Design Methodology) ► used in the analysis and design stages of systems development. SSADM does not cover Strategic Information Planning (SITP) issues or the construction, testing and implementation of software. ► "SSADM has been used by the government in computing since its launch in It was commissioned by the CCTA (Central Computing and Telecommunications Agency) ► SSADM is an open standard, i.e. it is freely available for use in industry and many companies offer support, training and Case tools for it.

Why is SSADM Used? ► Within government departments SSADM has to be used? External contractors producing software for the government also have to use SSADM? ► SSADM is used by other companies because they expect the use of a disciplined ‘engineering approach will eventually improve the quality of the systems they produce.

How is SSADM Structured? ► It has seven stages numbered 0 to 6  Feasibility ► It is technically possible and the benefits of the information system will outweigh the cost  Requirements analysis ► Investigation of current environment  Requirements Specification ► Definition of requirements  Logical System Specification ► Technical system options and logical design  Physical design ► Prepare for physical design ► Create physical data design ► Create function component implementation map ► And so on

What is SSM? ► Soft system Methodology  Developed as a response to hard systems and it’s failure to address messy situations. ► Organise our thinking systemically but recognising that the perceived is problematic

Seven stages 1. The problem situation unstructured.  The first two stages are concerned with finding out about the problem situation from as many people in that situation as possible 2. Problem situation expressed  Expressed in a formal way a method of doing this is to draw a rich picture of the situation. The rich picture is used as an aid in discussion between the problem solver and the problem owner.

3:Root definition of relevant system ► several different relevant systems should be explored to see which is the most useful.  At this stage that debate is most important. The problem owner and problem solver decide which view to focus on, that is how to describe their relevant system. ► After constructing a rich picture a root definition is developed for the relevant system. The root definition is a concise, tightly constructed description of a human activity system which states what the system is (Checkland,1981). ► Using a CATWOE checklist technique the root definition is created.

CATWOE ► Clients -people affected by the system ► Actors -people who are part of the system ► Transformation -the process done by system ► Worldview -describes the system ► Owners -people who affect/kill the system ► Environment -influences the system

4: Building Conceptual models ► When satisfied that the root definition is well formed a conceptual model can be developed ► A conceptual model is a diagram of the activates showing what the system will do as described by the root definition

5: Comparing conceptual models with reality 5: Comparing conceptual models with reality ► Comparison of the problem situation analysed in stage 2 through rich pictures alongside the conceptual models created in stage 4 ► Debate about possible changes should lead to set of recommendations regarding change in order to help the problem

6: Assessing feasible and desirable changes ► Concerns an analysis of proposed changes from stage 5 so to draw up proposals for those changes

7:Action to improve problem situation ► Final stage about recommending action to help the problem situation ► This type of methodology helps understand the problem situation rather than a scheme for solving a particular problem.

Methodology Stage Comparison SSADMJSDETHICSSSM StrategySomeYes FeasibilityYesSomeSome AnalysisYesSomeYesYes Logical Design YesYesYes Physical Design YesYesSome ProgrammingYes TestingSome ImplementationSomeLittle EvaluationLittle Maintenance Adapted from: Avison and Fitzgerald Information Systems Development: Methodologies, Techniques and Tools, 3 rd edn., 2003, Page 568.

Web Methodology Disciplines Web Engineering Hypertext Information Engineering Requirements Engineering System Analysis and Design Multimedia Human-Computer Interaction Testing Project Management Software Engineering Modelling and Simulation from: Murugesan et al, Web Engineering: A New Discipline for Development of Web-Based Systems, in “Web Engineering: Managing Diversity and Complexity of Web Application Development, Page 8

WSDM (pronounced Wisdom)

Web Site Design Method (WSDM) ► Has a focus on designing kiosk web-sites ► Systems with many user types / walk up and use ► Follows a ‘user centred’ focus rather than ‘data centred’ (information) approach ► To do so need to identify different types of user e.g. student, prospective student, lecturer, etc. ► Then produce a site that is sensitive to the given user types ► May result in different pages or paths being provided in a site for each type of user ► Starts to lay the foundations for the principles of localization and internationalization

© Prof. Dr. Olga De Troyer 2002 WSDM: Conceptual Design Mission statement: purpose target audience subject Audience Class Description Requirements: Information Functional Usability Characteristics Audience Class Hierarchy Object Chunk C1 Visitor PC-Chair Author Reviewe PC-Member Conceptual Design Mission statement Specification Audience Modeling Audience Classification Audience Class Characterization Navigational Design Task Modeling Implementation design Page Design Presentation Design Data Design Implementation

► Phase: Mission Statement ► Purpose ► Subject ► Target audience eg. “To support the overall selection process (submission by authors, evaluation, and selection by the Program Committee) of papers for a conference.” from: “The Conference Review System with WSDM”, Troyer, Olga De and Casteleyn, Sven (2001) Web Site Design Method (WSDM)

► Phases and steps: Phase: Audience modelling - All users have specific information wants and needs, we need to know these and design for them - All users have specific information wants and needs, we need to know these and design for them Step1: Audience classification - We need at this point to identify activities within the website and the relationship a given user type has with these - We need at this point to identify activities within the website and the relationship a given user type has with these - Identify users and classify them into specific “user classes” (e.g. lecturer, or student etc.). - Identify users and classify them into specific “user classes” (e.g. lecturer, or student etc.). - All user classes exist under a wider overall and complete set of given users - All user classes exist under a wider overall and complete set of given users

Web Site Design Method (WSDM) Step 2: Audience class characterisation - Further user classes analysis - Further user classes analysis - Identify specific information requirements, the - Identify specific information requirements, the “conceptual what” that the user class wants “conceptual what” that the user class wants - May diverge on actual information presentation, - May diverge on actual information presentation, e.g. salesman and car buyer have different e.g. salesman and car buyer have different requirements for advertising information requirements for advertising information - Analyze characteristics of user class, the - Analyze characteristics of user class, the “conceptual who”, e.g. levels of experience, “conceptual who”, e.g. levels of experience, frequency of use, motivation, & language etc. frequency of use, motivation, & language etc.

Web Site Design Method (WSDM) Phase: Conceptual design Step 1: Task modeling - We formally describe information requirements for the different user classes - We formally describe information requirements for the different user classes - Done via Object Role Model (ORM), Entity Relationship Model (ERM), etc. – gives a view of information required in the system - Done via Object Role Model (ORM), Entity Relationship Model (ERM), etc. – gives a view of information required in the system CustomerAccountHasFor a

Web Site Design Method (WSDM) Step 1: Task modeling (cont.) ► Also need to think about the functionality ► Expand on functional requirements set out in Audience Class Characterisation and model it using, for instance Hierarchical Task Analysis (HTA) or perhaps an Entity Life History (ELH) diagram

Web Site Design Method (WSDM) Step 2: Navigational design ► Construct a conceptual navigation model ► It consists of a number of navigation tracks – one for each audience class ► Association of information chunks – Information as components ► Association of functional chunks – Functions as components

© Prof. Dr. Olga De Troyer 2002 Conceptual Structural Model (3)  Conditional links may be needed Visitor Track Un-Registered User Track Registered User Track PC-chair Track Author Track Fully Registered User Track Pre-Registered User Track Reviewer Track PC-Member Track C1: visitor is not fullRegistered C2: visitor is fullRegistered C3: visitor is PC-Chair C4: visitor is Reviewer or p in PC-Member C5: visitor is PC-Member C6: visitor is PC-Author C1 C2 C3 C4 C5 C6

Web Site Design Method (WSDM) ► Phase: Implementation design ► Page design ► Presentation design ► Data design ► Phase: Implementation ► Produces the end product of a web-site

© Prof. Dr. Olga De Troyer 2002 WSDM: Conceptual Design Mission statement: purpose target audience subject Audience Class Description Requirements: Information Functional Usability Characteristics Audience Class Hierarchy Object Chunk C1 Visitor PC-Chair Author Reviewe PC-Member Conceptual Design Mission statement Specification Audience Modeling Audience Classification Audience Class Characterization Navigational Design Task Modeling Implementation design Page Design Presentation Design Data Design Implementation

Storyboards Simple paper based technique Simple paper based technique Basically pictures and text to roughly illustrate the make up / appearance of a screen Basically pictures and text to roughly illustrate the make up / appearance of a screen Not intended to be totally accurate, Not intended to be totally accurate, Limited on interaction, but Limited on interaction, but shows screen sequences shows screen sequences Each screen is accompanied Each screen is accompanied by text to describe the scene, by text to describe the scene, user interaction and any user interaction and any dynamic media (e.g. sound) dynamic media (e.g. sound) shown on a timeline

Conclusion

Methods ► General problems to overcome…  Favourite methodology  Used to justify a pre-defined solution ► Power of the analyst vs power of the person/organisation purchasing the system  Methodologies attempt to formalise messy human based systems

Methods ► Why use one? – some reasons…  Documentation – transparency, communication  Standardisation – of approach, across groups  Modelling – tools, techniques for representation  Evaluation – validation, verification

Assignment?

On-Line Bank ► WISDM  Mission Statement  Audience Classes  Audience Characterisation

For the tutorial… ► Think about…(in WSDM terms)  Task Modelling ► Information requirements of your audience ► Functional requirements of your audience  Navigation Design (for each audience class) ► Read: Paper.PDF Paper.PDF Paper.PDF ► Familiarise/re-familiarise yourself with ERM’s and ELH’s/HTA’s