UserCentered Development Methodology

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User-Centered DevelopmentMethodology

• A user interface comprises
• those aspects of the system that the user comes
  in contact with.
• Moran 1981

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User-Centered DevelopmentMethodology

• Centered on the USER not the Data
• Involves users in the whole process
• Usability can be quantified gtmeasured
• Interdisciplinary
• Draws from many disciplines
• Highly iterative
• Involves repeated testing and revision
• Techniques to test and debug interfaces before
  implementing them

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Fields HCI builds upon

• Computer Science
• Implementation of website or other interface
• Engineering
• Faster, cheaper equipment
• Ergonomics
• Design for human factors
• Graphic design
• Visual communication
• Technical writing
• Textual communication

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Fields HCI builds upon

• Linguistics, artificial intelligence
• Speech recognition, natural language processing
• Cognitive psychology
• Perception, memory, mental models
• Sociology
• How people interact in groups
• Anthropology
• Study of people in their work settings
• A highly eclectic field which offers both
  challenges and satisfactions

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User-Centered Methodology

• Initial stages involve gathering of information
• Needs Analysis
• User and task analysis
• Functional analysis
• Requirements analysis
• Setting usability specifications
• Later stages involve designing, building, and
  testing
• Design
• Prototyping
• Implementation
• Evaluation

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Needs analysis

• Summarizes the nature and purpose of the system
• Type of system (website, video game, spreadsheet)
• People it will serve
• Benefits it will provide
• This is normally very brief. Two or three
  sentences explaining why it is a good idea.

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User and task analysis

• User analysis - characterizes those who will use
  the site
• General considerations (age, education,
  experience with computers)
• Users' experience and expectations
• Task analysis - what users will do
• Users goals - what they want to accomplish
• Tasks or activities carried out to achieve the
  goals

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Functional analysis

• Functionality -computer services needed by users
  
• Close correspondence between functions and tasks
• What to automate
• on-line reservation or phone call
• Examples travel site task find all flights to
  xyz, ordered by price
• Needs search function and sorting capability
• Music CD site task buy a CD
• Needs secure on-line transaction functionality

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Requirements analysis

• Describes the formal specifications required to
  implement the system
• Data dictionaries
• Entity-relationship diagrams
• Object oriented modeling
• Covered in great detail in software engineering
  courses.

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Setting usability specifications

• Answers question How good is your site?
• Set usability specifications
• Performance measures Observable user behavior
  such as number of tasks completed, number of
  errors, etc.
• Preference measures insights into user opinion
  about site such as first impression, overall
  satisfaction.

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Design

• Make decisions about
• Organization
• Visual organization to create clarity and
  consistency
• Layout
• navigation
• Appearance
• Look and feel
• Now you can begin to sketch the pages
• Because you know your users and what they want to
  do

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Prototyping

• Prototype is an original model or pattern
• Global entire site
• Local selected parts of the site
• Prototypes
• Evolutionary becomes the final project
• Throw-away serves as a pattern
• High fidelity resembles final product
• Low fidelity just rough sketch - not close to
  final

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A low-fidelity prototype
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A high-fidelity prototype
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Implementation

• This is where the website or other interface is
  implemented, in HTML or a programming language

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Evaluation

• Expert-based evaluation
• Bring in a usability expert
• User-based evaluation
• Test the website or other interface with users
• In this class we will emphasize user-based
  evaluation

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User-Centered Characteristics

• Highly iterative

NO
YES
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User-Centered Design

• Is industry-proven
• Lets you build websites or interfaces that meet
  user expectations
• Leads to cost-effective and timely implementation
  
• Is highly interactive
• You have also learned that HCI is a highly
  eclectic field, building on a dozen other
  disciplines