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