user centered design interactive software...
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User Centered Design
Interactive Software Lifecycle
Universidade de Aveiro
Departamento de Electrónica,
Telecomunicações e Informática
Human-Computer Interaction Beatriz Sousa Santos, 2016/2017
http://www.usability.gov/
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User centered design of interactive systems
• Complementary approaches to the design:
Usability principles (technology independent)
Usability paradigms (more technology dependent)
Guidelines and standards (more specific)
• S/W development technologies
• Evaluation
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• We must know the successful cases (usability paradigms)
• Understand why they work (usability principles)
• Adopt adequate methodologies
• And test, re-design, test, re-design
…
until usability goals are met
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• ISO standard 13407 (1999) - Human centered design processes for interactive
systems:
"Human-centered design is an approach to interactive system development that focuses specifically on making systems usable. It is a multi-disciplinary activity."
• There are several proposals of UCD methodologies
• All are iterative
• And include usability evaluation in iterations
https://www.w3.org/WAI/redesign/ucd
http://www.usability.gov/how-to-and-tools/methods/user-research/index.html
Benefits of user-centered design (UCD)
• Following UCD best practices, helps to identify challenges upfront so that a
solution can be found early
• By putting a larger emphasis on UCD principles and practices, iterative
improvements can be made and avoid costly large scale rework
• The“10%” rules:
– 10% of IT staff should be user experience (UX) professionals
– 10% of budget dedicated to UX.
5 http://www.usability.gov/what-and-why/benefits-of-ucd.html
Top 12 reasons IEEE identified for why IT projects fail
(three can be fixed by using adequate UX methods)
• Unrealistic or unarticulated project goals
• Inaccurate estimates of needed resources
• Badly defined system requirements
• Poor reporting of the project's status
• Unmanaged risks
• Poor communication among customers, developers, and users
• Use of immature technology
• Inability to handle the project's complexity
• Sloppy development practices
• Poor project management
• Stakeholder politics
• Commercial pressures
http://spectrum.ieee.org/computing/software/why-software-fails
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May be alleviated by good UX design
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http://www.usability.gov/how-to-and-tools/methods/user-research/index.html
User Research Methods
• Usability testing
• Context interviews
• First click tests
• Focus groups
• Individual interviews
• On-line surveys
• Personas
• Scenarios
• Task analysis
8 (Mayhew, 1999, chap.1)
Example of a UCD
methodology:
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Establish user characteristics important for UI design Obtain a user-centered model of work as it is currently done; extract the product usability requirements Establish specific quantitative and qualitative usability goals to drive UI design Establish capabilities and constraints of the technology platform which limit UI design alternatives Identify principles and guidelines that may be relevant for the product under development
User Profiles
Contextual Task
Analysis
Usability Goal
Setting
Platform Capabilities
and Constraints
General Design
Principles
Requirement Analysis
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Reengineer the current user work model to realize the potential of automation and more effectively support business goals Establish a coherent and rule based, high level UI design framework to set the stage for design at lower levels Support evaluation, refinement, and validation of the Conceptual Model Design Evaluate, refine and validate the Conceptual Model Design
Work Reengineering
Conceptual Model
Design
Conceptual model
Mock-ups
Iterative Conceptual
Model Evaluation
Design, Testing, Development – Level 1
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Establish a set of design standards to set the stage for detailed UI Design Support the evaluation, refinement and validation of the Screen Design Standards Evaluate, refine, and validate the Screen Design Standards Document the Conceptual Model Design, the Screen Design Standards and the output of Requirement Analysis
Screen Design
Standards
Screen Design
Standards
Prototyping
Iterative Screen
Design Standards
Evaluation
Style Guide
Development
Design, Testing, Development – Level 2
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Design the complete, detailed
product User Interface
Evaluate, refine, and validate
key subsets of the detailed User
Interface Design
Obtain usability data after a
product has been installed
and used
Inform the UI Design for later
releases or related products
Detailed User Interface
Design
Iterative User Interface
Evaluation
User Feedback
Design, Testing, Development – Level 3
Installation
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General Philosophy behind the Usability Eng. Lifecycle (Mayhew, 1999)
• User interface design is key
• Integration of Usability Eng. with S/W Eng. must be tailored
• Requirements analysis pays off
• Design can be approached in a top down, structured process
• Design, testing, and development should be iterative
• The whole lifecycle can be layered across subsets of functionality
• There are several techniques for carrying out each lifecycle task
• Alternative techniques make the lifecycle flexible and adaptable
• Optimal implementation of the lifecycle requires cross-functional teams
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User Interface design
(from a S/W engineering perspective)
(Sommerville, 2010, cap.29)
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Non-functional requirements
(Sommerville, 2010)
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Main Bibliography
Main bibliography
• Deborah Mayhew, The Usability Engineering Lifecycle, Morgan
Kaufmann, 1999
• Ian Sommerville, Software Engineering, 9th ed., Addison Wesley, 2010
http://ifs.host.cs.st-
andrews.ac.uk/Books/SE9/WebChapters/PDF/Ch_29%20Interaction_design.pdf
Interesting Links
• https://www.nngroup.com/
• http://www.usability.gov/
• http://uxpa.org/
• https://www.w3.org/WAI/redesign/ucd