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HCI StandardsHCI Standards

Lecture 15Date: 30th March

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Overview of Lecture

•Standards & Standard bodies

•Types of HCI standards

•EC Council Directive

•Metrics

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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 9241ISO 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 standardsAdvantages of standards•Lead to consistency•Users can learn how to use systems easily if they follow well known standards (otherwise can’t) – improves learnability, usability and transfer of knowledge to new systems

•Disadvantages of standardsDisadvantages 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

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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

DevelopmentDevelopmentProcessProcess

Life CycleLife CycleProcessProcess

ISO 9241 ISO 9241ISO/IEC FCD 18021

ISO 13406ISO AWI 18789ISO/IEC 14754

User User Interface & Interface & InteractionInteraction

Product UseProduct Use

ISO 13407ISO TR 16982

ISO TR 18529

Types of HCI Standards

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Product UseISO 9241-11: Guidance on Usability (1998)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

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Interface & Interaction

•ISO 9241ISO 9241: Ergonomic requirements for office work with visual display terminals

•ISO/IEC FCD 18021ISO/IEC FCD 18021: Information Technology - User Interface for mobile tools (2001)

•ISO 13406ISO 13406: Ergonomic requirements for work with visual displays based on flat panels

•ISO AWI 18789ISO AWI 18789: Ergonomic requirements and measurement techniques for electronic visual displays (1999)

•ISO/IEC 14754ISO/IEC 14754: Pen-based interfaces - Common gestures for text editing with pen-based systems (1999)

Types of HCI Standards

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Interface & InteractionISO 9241: Ergonomic requirements for office work with ISO 9241: Ergonomic requirements for office work with

visual display terminalsvisual 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 ISO 9241: Ergonomic requirements for office work with visual display terminalsvisual 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

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Interface & Interaction

ISO AWI 18789: Ergonomic requirements and ISO AWI 18789: Ergonomic requirements and measurement techniques for electronic visual displays measurement techniques for electronic visual displays (1999)(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 ISO 13406: Ergonomic requirements for work with visual displays based on flat panelsvisual displays based on flat panelsThis 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

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Interface & Interaction

ISO/IEC FCD 18021: ISO/IEC FCD 18021: Information Technology - User Information Technology - User Interface for mobile tools (2001) 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 ISO/IEC 14754: Pen-based interfaces - Common gestures for text editing with pen-based systems gestures for text editing with pen-based systems

(1999)(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

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Development Process

•ISO 13407ISO 13407: Human-centred design processes for interactive systems (1999)

•ISO TR 16982: ISO TR 16982: Usability methods supporting human Usability methods supporting human

centred design (2001)centred design (2001)

Types of HCI Standards

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Development Process

ISO 13407: Human-centred design processes for ISO 13407: Human-centred design processes for

interactive systems (1999)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

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Development Process

ISO TR 16982: ISO TR 16982: Usability methods supporting human Usability methods supporting human centred design (2001)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

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Life Cycle Process

ISO TR 18529: Ergonomics of human-system interaction ISO TR 18529: Ergonomics of human-system interaction

- Human-centred lifecycle process descriptions (2000)- 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 ISO 9241 Part 1: Ergonomic requirements for office work with visual display terminals (VDTs) - Part 1: work with visual display terminals (VDTs) - Part 1: General Introduction (1997)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 2:Guidance on task requirements ISO 9241-2 Part 2:Guidance on task requirements (1992(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-ISO DTS 16071: Guidance on accessibility for human-

computer interfaces (2000)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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CommercialStyleGuides

CorporateStyleGuides

Miscellaneous

House Style Guides

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Commercial Style GuidesCommercial 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 GuidesCorporate Style Guides

• Organisations use style guides for their own internal use

Miscellaneous

House Style Guides

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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 system’s 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

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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

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

Miscellaneous

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Metrics

Operator Description Time (sec)

K Pressing a single key or buttonAverage skilled typist (55 wpm)Average non-skilled typist (40 wpm)Pressing shift or control keyTypist unfamiliar with the keyboard

0.220.280.081.20

P

P1

Pointing with a mouse or other deviceon a display to select an object.

Clicking the mouse or similar device

1.10

0.20

H Bring ‘home’ hands on the keyboard or other device

0.40

M Mentally prepare/respond 1.35

R(t) System response time is counted onlyif it causes the user to wait.

t

0.35

D Draw a line with a mouse Variable - depends on line

Keystroke ModelKeystroke 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

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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

Summary

•Standards & Standard bodies•Types of HCI standards

•Product use•User interface and interaction•Development process•Lifecycle process

•EC Council Directive•Metrics

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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