HCI Standards

1
HCI Standards

• Lecture 15
• Date 30th March

2
Overview of Lecture

• Standards Standard bodies
• Types of HCI standards
• EC Council Directive
• Metrics

3
Why Standards?

• Standards exist for most everyday items in our
  houses eg. standard brick sizes, food labels
  etc.
• Software standards
• Standards are developed and promoted by a number
  of organizations for a number of reasons
• In software industry, standards have become a
  major topic and area of advances

Standards Standard bodies
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Standards Standards Bodies

• Two major international standards bodies
• The International Organization for
  Standardization (ISO)
• ISO 9000 is concerned with general software
  quality
• The International Electrochemical Commission
  (IEC)
• Main standard relevant to HCI is ISO standard
  9241
• ISO works closely with national standard bodies
  such as the American National Standards Institute
  (ANSI)
• Standards are drafted by technical committees
  whose members are nominated by manufactures,
  trade and research associations

Standards Standard bodies
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Standards Standards Bodies

• Governments
• E.g. UK Ministry of Defense
• In the U.S. same thing
• Professional bodies
• IEEE
• British Computing Society (BCS)
• Industry standards
• E.g. Microsoft standards, Mac standards
• De facto standards
• E.g. the qwerty keyboard
• Not dictated by a country or company but just end
  up becoming the standard
• House standards
• House style guidelines in large organizations
  developing software

Standards Standard bodies
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Standards Standards Bodies

• Advantages of standards
• Lead to consistency
• Users can learn how to use systems easily if they
  follow well known standards (otherwise cant)
  improves learnability, usability and transfer of
  knowledge to new systems
• Disadvantages of standards
• There is a lot of human variability and
  preferences regarding styles etc. (some like
  menus, others, may like other styles of
  interaction etc.) may depend on experience,
  background etc. hard to set standards to please
  everyone
• Can restrict innovation and freeze new advances
  and thwart creativity in design e.g. if were
  around 30 years ago might have precluded things
  like development of the mouse etc.

Standards Standard bodies
7
Types of HCI Standards

• Standards related to usability can be categorized
  as primarily concerned with
• the use of the product
• the user interface and interaction
• the process used to develop the product
• the capability of an organization to apply user
  centered design

Types of HCI Standards
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Types of HCI Standards
Development Process
Life Cycle Process
User Interface Interaction
Product Use
ISO 9241 ISO/IEC FCD 18021 ISO 13406 ISO AWI
18789 ISO/IEC 14754
ISO 13407 ISO TR 16982
ISO TR 18529
ISO 9241
Types of HCI Standards
9
Product Use

• ISO 9241-11 Guidance on Usability (1998)
• Defines usability as the extent to which a
  product can be used by specified users to achieve
  specified goals with effectiveness, efficiency
  and satisfaction in a specified context of use
• Explains how to identify the information that is
  necessary to take into account when specifying or
  evaluating usability in terms of measures of user
  performance and satisfaction
• Guidance is given on how to describe the context
  of use of the product and the measures of
  usability in an explicit way
• Explains how measures of user performance and
  satisfaction can be used to measure how any
  component of a system works

Types of HCI Standards
10
Interface Interaction

• ISO 9241 Ergonomic requirements for office work
  with visual display terminals
• ISO/IEC FCD 18021 Information Technology - User
  Interface for mobile tools (2001)
• ISO 13406 Ergonomic requirements for work with
  visual displays based on flat panels
• ISO AWI 18789 Ergonomic requirements and
  measurement techniques for electronic visual
  displays (1999)
• ISO/IEC 14754 Pen-based interfaces - Common
  gestures for text editing with pen-based systems
  (1999)

Types of HCI Standards
11
Interface Interaction

• ISO 9241 Ergonomic requirements for office work
  with visual display terminals
• ISO 9241 provides requirements and
  recommendations relating to the attributes of the
  hardware, software and environment that
  contribute to usability, and the ergonomic
  principles underlying them.
• Part 10 Dialogue principles
• Part 12 Presentation of information
• Part 13 User guidance (1998)
• Part 14 Menu dialogues (1997)
• Part 15 Command dialogues (1997)
• Part 16 Direct manipulation dialogues (1999)
• Part 17 Form filling dialogues (1998)

Types of HCI Standards
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Interface Interaction

• ISO 9241 Ergonomic requirements for office work
  with visual display terminals
• Parts 3 to 9 contain hardware design requirements
  and guidance.
• Part 3 Visual display requirements (1992)
• Part 4 Keyboard requirements (1998)
• Part 5 Workstation layout and postural
  requirements (1998)
• Part 6 Guidance on the work environment (1999)
• Part 7 Requirements for display with reflections
  (1998)
• Part 8 Requirements for displayed colours
• Part 9 Requirements for non-keyboard input
  devices (2000)

Types of HCI Standards
13
Interface Interaction

• ISO AWI 18789 Ergonomic requirements and
  measurement techniques for electronic visual
  displays (1999)
• This standard is intended to revise and replace
  ISO 9241 Parts 3, 7 and 8 and ISO 13406.
• ISO 13406 Ergonomic requirements for work with
  visual displays based on flat panels
• This standard establishes ergonomic image-quality
  requirements for the design and evaluation of
  flat panel displays and specifies methods of
  determining image quality.

Types of HCI Standards
14
Interface Interaction

• ISO/IEC FCD 18021 Information Technology - User
  Interface for mobile tools (2001)
• This standard contains user interface
  specifications for PDA's with a data interchange
  capability with corresponding servers.
• ISO/IEC 14754 Pen-based interfaces - Common
  gestures for text editing with pen-based systems
  (1999)
• This standard defines a set of basic gesture
  commands and feedback for pen interfaces. The
  gestures include select, delete, insert space,
  split line, move, copy, cut, paste, scroll and
  undo.

Types of HCI Standards
15
Development Process

• ISO 13407 Human-centred design processes for
  interactive systems (1999)
• ISO TR 16982 Usability methods supporting human
  centred design (2001)

Types of HCI Standards
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Development Process

• ISO 13407 Human-centred design processes for
  interactive systems (1999)
• Provides guidance on human-centred design
  activities throughout the life cycle of
  interactive computer-based systems.
• A tool for those managing design processes and
  provides guidance on sources of information and
  standards relevant to the human-centred approach.
  
• The recommended process is shown in the next
  slide.

Types of HCI Standards
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Development Process
Types of HCI Standards
18
Development Process

• ISO TR 16982 Usability methods supporting human
  centred design (2001)
• This technical report outlines the different
  types of usability methods that can be used to
  support user centred design

Types of HCI Standards
19
Life Cycle Process

• ISO TR 18529 Ergonomics of human-system
  interaction - Human-centred lifecycle process
  descriptions (2000)
• This Technical Report contains a structured and
  formalised list of human-centred processes
• HCD.1 Ensure HCD content in system strategy
• HCD.2 Plan and manage the HCD process
• HCD.3 Specify the user and organisational
  requirements
• HCD.4 Understand and specify the context of use
• HCD.5 Produce design solutions
• HCD.6 Evaluate designs against requirements HCD.7
  Introduce and operate the system

Types of HCI Standards
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Other Related Standards

• ISO 9241 Part 1 Ergonomic requirements for
  office work with visual display terminals (VDTs)
  - Part 1 General Introduction (1997)
• This part introduces the multi-part standard ISO
  9241 for the ergonomic requirements for the use
  of visual display terminals for office tasks and
  explains some of the basic underlying principles.
  
• ISO 9241-2 Part 2Guidance on task requirements
  (1992)
• Deals with the design of tasks and jobs involving
  work with visual display terminals. It provides
  guidance on how task requirements may be
  identified and specified and how task
  requirements can be incorporated into the system
  design and implementation process.

Types of HCI Standards
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Other Related Standards

• ISO DTS 16071 Guidance on accessibility for
  human-computer interfaces (2000)
• Provides guidelines and recommendations for the
  design of systems and software that will enable
  users with disabilities greater accessibility to
  computer systems (with or without assistive
  technology).   It includes low vision users,
  hearing impaired users, deaf users, users with
  physical and cognitive impairments, and the
  elderly.

Types of HCI Standards
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EC Council Directive

• Issued in May 1990
• Addresses minimum safety and health requirements
  for work with display screen equipment
• High impact on HCI design practice
• Any directives from EU are binding for member
  states (overriding national standards)
• Penalties for non compliance defined at national
  level

EC Council Directive
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EC Council Directive

• Examples of contents
• Display screen
• well defined clear characters
• stable flicker free image
• adjustable brightness and/or contrast
• easy swivel/tilt
• Keyboard
• Tiltable and separate from display
• non reflective surfaces
• Computer interface
• easy to use
• adapted to users level of knowledge
• system to provide feedback to user

EC Council Directive
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EC Council Directive

• Many exclusions
• computer systems on means of transport
• computer systems for public use
• portable systems
• point of sale equipment

EC Council Directive
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House Style Guides
Commercial Style Guides
Corporate Style Guides
Miscellaneous
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House Style Guides

• Commercial Style Guides
• Produced by hardware and software manufacturers
• Mostly low level design rules (rather than
  principles)
• Enables distinct look and feel across familes of
  products from vendors (such as IBM, Apple,
  Microsoft)
• Extensive IBM guide - 600 pages
• Corporate Style Guides
• Organisations use style guides for their own
  internal use

Miscellaneous
27
Metrics

• If standards are going to be meaningful, we must
  have a way of expressing fairly precisely the
  quality level we expect, and a way of measuring
  the systems performance against the standards
• Informal measurement is better than no
  measurement
• Numerical measures of the products and processes
  of software development are called software
  metrics

Miscellaneous
28
Metrics

• Within a project there are many types of metrics
• Metrics for the functional complexity of a system
• Metrics for the inter-module and intra-module
  connectivity of a system
• Metrics for the amount of effort required to
  develop a system
• Metrics for interface development, just as for
  other elements of a system
• Can be more objective than just opinion
• E.g. rather than saying I like this interface
  design better you can say Interface A took me 5
  minutes longer to perform the task than interface
  B

Miscellaneous
29
Metrics

• Duration metrics
• Measure how much time is spent doing a particular
  task, e.g. time spent looking at on-line help
  screens
• Count measures
• Simply count how many times an event happens, or
  how many discrete activities are performed, e.g.
  how many error are made
• Proportion of task completed
• It is not easy to measure how much of a task has
  been completed. However, it can be achieved by
  carefully setting the task goals and then
  counting how many have been completed after a
  certain time
• Quality of output
• Not easy to provide an absolute measure, but
  could have output rated using criteria

Miscellaneous
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Metrics

• What model could be used to provide actual
  numerical predictions of user performance?

Miscellaneous
31
Metrics
Keystroke Model
Miscellaneous
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Metrics

• Time taken to execute a given task
• Identify the sequence of actions involved
• Add the time take for each action together
• Texecute Tk Tp Th Td Tm Tr

Miscellaneous
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Metrics

• Example User asked to edit a sentence
• From Shouting loudly is normal
• To Shouting loudly is not normal
• Time taken by user to add not into sentence is
• decide what to do (M)
• Move cursor to appropriate point in sentence (H)
• Position mouse before the word normal (P)
• Click mouse button (P1)
• Move hand over keyboard to type (H)
• Think about letters to type (M)
• Types letters n, o, t (3K)
• Press spacebar (K)

Miscellaneous
34
Metrics

• decide what to do (M) 1.35
• Reach for the mouse (H) 0.40
• Position mouse before the word normal (P) 1.10
• Click mouse button (P1) 0.20
• Move hand over keyboard to type (H) 0.40
• Think about letters to type (M) 1.35
• Types letters n, o, t (3K) - good typist 0.66
• Press spacebar (K) 0.22
• Total predicted time 5.68sec

Miscellaneous
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Summary of Lecture

• Standards Standard bodies
• Types of HCI standards
• Product use
• User interface and interaction
• Development process
• Lifecycle process
• EC Council Directive
• Metrics

Summary
36
Terms of Reference

• Shneiderman, B. Plaisant, C. (2005) Designing
  the User Interface
• Preece, J. et al. (2002) Interaction Design
• Benyon, D. et al (2005) Designing Interactive
  Systems
• ISO www.iso.org
• IEC www.iec.org

References