DIN EN ISO 9241-171-2008 Ergonomics of human-system interaction - Part 171 Guidance on software accessibility (ISO 9241-171 2008) English version of DIN EN ISO 9241-171 2008-10《人机交.pdf

1、October 2008DEUTSCHE NORM English price group 31No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 13.180; 35.080!$RSg“14

2、74868www.din.deDDIN EN ISO 9241-171Ergonomics of human-system interaction Part 171: Guidance on software accessibility (ISO 9241-171:2008)English version of DIN EN ISO 9241-171:2008-10Ergonomie der Mensch-System-Interaktion Teil 171: Leitlinien fr die Zugnglichkeit von Software (ISO 9241-171:2008)En

3、glische Fassung DIN EN ISO 9241-171:2008-10www.beuth.deDocument comprises 97 pagesDIN EN ISO 9241-171:2008-10 2 National foreword This standard has been prepared by Technical Committee ISO/TC 159 “Ergonomics”, Subcommittee SC 4 “Ergonomics of human-system interaction”, Working Group WG 5 “Software e

4、rgonomics and human-computer dialogues” in collaboration with Technical Committee CEN/TC 122 “Ergonomics” (Secretariat: DIN, Germany). The responsible German body involved in its preparation was the Normenausschuss Ergonomie (Ergonomics Standards Committee), Joint Technical Committee NA 023-00-04 GA

5、 Ergonomie fr Informationsverarbei-tungssysteme, Joint Working Group NA 023-00-04-06 GAK Barrierefreie Informationstechnologie/ Accessibil-ity. In the meantime, this standard is under the responsibility of Joint Technical Committee NAErg/NIA Grund-lagen zur barrierefreien Gestaltung/Accessibility. T

6、he DIN Standards corresponding to the International Standards referred to in the EN are as follows: ISO 9241-11 DIN EN ISO 9241-11 ISO 9241-12 DIN EN ISO 9241-12 ISO 9241-13 DIN EN ISO 9241-13 ISO 9241-14 DIN EN ISO 9241-14 ISO 9241-15 DIN EN ISO 9241-15 ISO 9241-16 DIN EN ISO 9241-16 ISO 9241-17 DI

7、N EN ISO 9241-17 ISO 9241-110 DIN EN ISO 9241-110 ISO 13407 DIN EN ISO 13407 ISO 14915 (all Parts) DIN EN ISO 14915 (all Parts) National Annex NA (informative) Bibliography DIN EN ISO 9241-11, Ergonomic requirements for office work with visual display terminals (VDTs) Part 11: Guidance on usability

8、DIN EN ISO 9241-12, Ergonomic requirements for office work with visual display terminals (VDTs) Part 12: Presentation of information DIN EN ISO 9241-13, Ergonomic requirements for office work with visual display terminals (VDTs) Part 13: User guidance DIN EN ISO 9241-14, Ergonomic requirements for o

9、ffice work with visual display terminals (VDTs) Part 14: Menu dialogues DIN EN ISO 9241-15, Ergonomic requirements for office work with visual display terminals (VDTs) Part 15: Command dialogues DIN EN ISO 9241-16, Ergonomic requirements for office work with visual display terminals (VDTs) Part 16:

10、Direct manipulation dialogues DIN EN ISO 9241-171:2008-10 3 DIN EN ISO 9241-17, Ergonomic requirements for office work with visual display terminals (VDTs) Part 17: Form filling dialogues DIN EN ISO 9241-110, Ergonomics of human-system interaction Part 110: Dialogue principles DIN EN ISO 13407, Huma

11、n-centred design processes for interactive systems DIN EN ISO 14915 (all Parts), Software ergonomics for multimedia user interfaces DIN EN ISO 9241-171:2008-10 4 This page is intentionally blank EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 9241-171July 2008ICS 13.180English VersionErgonomic

12、s of human-system interaction - Part 171: Guidanceon software accessibility (ISO 9241-171:2008)Ergonomie de linteraction homme-systme - Partie 171:Lignes directrices relatives laccessibilit aux logiciels(ISO 9241-171:2008)Ergonomie der Mensch-System-Interaktion - Teil 171:171:2008)This European Stan

13、dard was approved by CEN on 28 June 2008.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such

14、 nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language an

15、d notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg,

16、 Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exp

17、loitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 9241-171:2008: ELeitlinien fr die Zugnglichkeit von Software (ISO 9241-2 DIN EN ISO 9241-171:2008-10 EN ISO 9241-171:2008 (E) Contents Page Foreword3 Introduction .4 1 Scope 6 2 Normative references 6 3

18、 Terms and definitions .7 4 Rationale and benefits of implementing accessibility 13 5 Principles for designing accessible software 13 6 Sources of variation in user characteristics14 7 How to use this part of ISO 9241. 15 7.1 General. 15 7.2 Conformance. 15 8 General guidelines and requirements 16 8

19、.1 Names and labels for user-interface elements 16 8.2 User preference settings 19 8.3 Special considerations for accessibility adjustments 21 8.4 General control and operation guidelines . 22 8.5 Compatibility with assistive technology 26 8.6 Closed systems. 31 9 Inputs . 31 9.1 Alternative input o

20、ptions . 31 9.2 Keyboard focus. 33 9.3 Keyboard input 34 9.4 Pointing devices . 40 10 Outputs 44 10.1 General output guidelines . 44 10.2 Visual output (displays) . 44 10.3 Text/fonts. 45 10.4 Colour 46 10.5 Window appearance and behaviour .47 10.6 Audio output 50 10.7 Text equivalents of audio (cap

21、tions) 52 10.8 Media 52 10.9 Tactile output 53 11 On-line documentation, “Help” and support services 53 11.1 Documentation and “Help” 53 11.2 Support services. 54 Annex A (informative) Overview of the ISO 9241 series. 56 Annex B (informative) List of requirements 60 Annex C (informative) Sample proc

22、edure for assessing applicability and conformance 62 Annex D (informative) Activity limitation issues. 73 Annex E (informative) Access features 79 Annex F (informative) Accessibility and usability 88 Bibliography. 90 3 Foreword This document (EN ISO 9241-171:2008) has been prepared by Technical Comm

23、ittee ISO/TC 159 “Ergonomics“ in collaboration with Technical Committee CEN/TC 122 “Ergonomics” the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by January 200

24、9, and conflicting national standards shall be withdrawn at the latest by January 2009. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights

25、. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy

26、, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 9241-171:2008 has been approved by CEN as a EN ISO 9241-171:2008 without any modification. EN ISO 9241-171

27、:2008 (E) DIN EN ISO 9241-171:2008-10 Introduction The purpose of this part of ISO 9241 is to provide guidance on the design of the software of interactive systems so that those systems achieve as high a level of accessibility as possible. Designing human-system interactions to increase accessibilit

28、y promotes increased effectiveness, efficiency and satisfaction for people having a wide variety of capabilities and preferences. Accessibility is therefore strongly related to the concept of usability (see ISO 9241-11). The most important approaches to increasing the accessibility of a human-system

29、 interface are adopting a human-centred approach to design (see ISO 13407), following a context-based design process, providing the capacity for individualization (see ISO 9241-110), and offering individualized user instruction and training. It is important to incorporate accessibility goals and fea

30、tures into the design as early as possible, when it is relatively inexpensive compared to the cost of modifying products to make them accessible once they have been designed. As well as providing guidance for achieving that, this part of ISO 9241 addresses the increasing need to consider social and

31、legislative demands for ensuring accessibility by the removal of barriers that prevent people from participating in life activities such as the use of environments, services, products and information. This part of ISO 9241 is applicable to software that forms part of interactive systems used in the

32、home, in leisure activities, in public situations and at work. Requirements and/or recommendations are provided for system design, appearance and behaviour, as well as specific accessibility issues, thereby complementing International Standards ISO 9241-11, ISO 9241-12, ISO 9241-13, ISO 9241-14, ISO

33、 9241-15, ISO 9241-16 and ISO 9241-17, ISO 9241-110 and ISO 14915, as well as reflecting the goals outlined in ISO Guide 7160. Conforming with the aforementioned International Standard is also important if the goal of accessibility is to be achieved. NOTE 1 While the requirements and recommendations

34、 of this part of ISO 9241 are generally applicable to all software application domains, additional detailed guidance on the accessibility of Web content (including Web applications) is available from the Web Content Accessibility Guidelines (WCAG) 53. This part of ISO 9241 is based on the current un

35、derstanding of the characteristics of individuals who have particular physical, sensory and/or cognitive impairments. However, accessibility is an issue that affects many groups of people. The intended users of interactive systems are consumers or professionals people at home, at school, engineers,

36、clerks, salespersons, Web designers, etc. The individuals in such target groups vary significantly as regards physical, sensory and cognitive abilities and each target group will include people with different abilities. Thus, people with disabilities do not form a specific group that can be separate

37、d out and then disregarded. The differences in capabilities can arise from a variety of factors that serve to limit the capability to engage in the activities of daily living, and are a “universal human experience” 50. Therefore, accessibility addresses a widely defined group of users including peop

38、le with physical, sensory and cognitive impairments present at birth or acquired during life, elderly people who can benefit from new products and services but who experience reduced physical, sensory and cognitive capacities, people with temporary disabilities, such as a person with a broken arm or

39、 someone who has forgotten his/her glasses, and people who experience difficulties in particular situations, such as a person who works in a noisy environment or has both hands occupied by other activities. 4 DIN EN ISO 9241-171:2008-10 EN ISO 9241-171:2008 (E) When designing and evaluating interact

40、ive systems there are other terms that are often associated with accessibility. In Europe, the expression design for all or, in North America, universal design 9, address the goal of enabling maximum access to the maximum number and diversity of users, irrespective of their skill level, language, cu

41、lture, environment or disability. This does not mean that every product will be usable by every consumer. There will always be a minority of people with severe or multiple disabilities who will need adaptations or specialized products. Accessibility as defined in this part of ISO 9241 emphasizes the

42、 goals of maximizing the number of users and striving to increase the level of usability that these users experience. This part of ISO 9241 recognizes that some users of software will need assistive technologies in order to use a system. In the concept of designing software to be accessible, this in

43、cludes the capability of a system to provide connections to, and enable successful integration with, assistive technologies, in order to increase the number of people who will be able to use the interactive system. Guidance is provided on designing software that integrates as effectively as possible

44、 with common assistive technologies. It is important to note that accessibility can be provided by a combination of both software and hardware controlled by software. Assistive technologies typically provide specialized input and output capabilities not provided by the system. Software examples incl

45、ude on-screen keyboards that replace physical keyboards, screen-magnification software that allows users to view their screens at various levels of magnification, and screen-reading software that allows blind users to navigate through applications, determine the state of controls, and read text via

46、text-to-speech conversion. Hardware examples include head-mounted pointing devices instead of mice and Braille output devices instead of a video display. There are many others. When users employ add-on assistive software and/or hardware, usability is enhanced to the extent that systems and applicati

47、ons integrate with those technologies. For this reason, platforms (including operating systems) must provide programming services to allow software to operate effectively with add-on assistive software and hardware as specified in this part of ISO 9241. If systems do not provide support for assistiv

48、e technologies, the probability increases that users will encounter problems with compatibility, performance and usability. This part of ISO 9241 serves the following types of users: designers of user-interface development tools and style guides to be used by interface designers; user-interface desi

49、gners, who will apply the guidance during the development process; developers, who will apply the guidance during the design and implementation of system functionality; those responsible for implementing solutions to meet end-user needs; buyers, who will reference this part of ISO 9241 during product procurement; evaluators, who are responsible for ensuring that products are in accordance with this part of ISO 9241. NOTE 2 In this document the term “developers” is used as shorthand for all those involved in the