1、BS EN ISO9241-171:2008ICS 13.180; 35.080NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDErgonomics of human-system interactionPart 171: Guidance on softwareaccessibility (ISO 9241-171:2008)Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 14/01/2010 03:10,
2、Uncontrolled Copy, (c) BSIThis British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 31 October2009 . BSI 2009ISBN 978 0 580 69257 4Amendments/corrigenda issued since publicationDate CommentsBS EN ISO 9241-171:2008National forewordThis British Standard is t
3、he UK implementation of EN ISO9241-171:2008.The UK participation in its preparation was entrusted to TechnicalCommittee PH/9, Applied ergonomics.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the neces
4、sary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 14/01/2010 03:10, Uncontrolled Copy, (c) BSIEUROPEAN STANDARDNORME EUROPENNEEUROPISCH
5、E NORMEN ISO 9241-171July 2008ICS 13.180English VersionErgonomics 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
6、Mensch-System-Interaktion - Teil 171:Leitlinien fr die Zugnglichkeit von Software (ISO 9241-171:2008)This European Standard 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 th
7、e status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such 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
8、). A version in any other language made by translationunder the responsibility of a CEN member into its own language and 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 Republ
9、ic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMA
10、LISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 9241-171:2008: ELicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 14/01/2010 0
11、3:10, Uncontrolled Copy, (c) BSIBS EN ISO 9241-171:2008EN ISO 9241-171:2008 (E) 3 Foreword This document (EN ISO 9241-171:2008) has been prepared by Technical Committee ISO/TC 159 “Ergonomics“ in collaboration with Technical Committee CEN/TC 122 “Ergonomics” the secretariat of which is held by DIN.
12、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 2009, and conflicting national standards shall be withdrawn at the latest by January 2009. Attention is drawn to the possibility that some o
13、f 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. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to impleme
14、nt this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland an
15、d 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. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 14/01/2010 03:10, Uncontrolled Copy, (c) BSIBS EN ISO 9241-171:2008ISO 9241-171:2008(E) ISO 2008
16、All rights reserved iiiContents Page Foreword iv Introduction . vi 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 2 4 Rationale and benefits of implementing accessibility 8 5 Principles for designing accessible software8 6 Sources of variation in user characteristics 9 7 How to use
17、this part of ISO 9241. 10 7.1 General. 10 7.2 Conformance. 10 8 General guidelines and requirements 11 8.1 Names and labels for user-interface elements 11 8.2 User preference settings 14 8.3 Special considerations for accessibility adjustments 16 8.4 General control and operation guidelines17 8.5 Co
18、mpatibility with assistive technology 21 8.6 Closed systems. 26 9 Inputs . 26 9.1 Alternative input options . 26 9.2 Keyboard focus. 28 9.3 Keyboard input 29 9.4 Pointing devices . 35 10 Outputs 39 10.1 General output guidelines . 39 10.2 Visual output (displays) . 39 10.3 Text/fonts. 40 10.4 Colour
19、 41 10.5 Window appearance and behaviour .42 10.6 Audio output 45 10.7 Text equivalents of audio (captions) 47 10.8 Media 47 10.9 Tactile output 48 11 On-line documentation, “Help” and support services 48 11.1 Documentation and “Help” 48 11.2 Support services. 49 Annex A (informative) Overview of th
20、e ISO 9241 series. 51 Annex B (informative) List of requirements. 55 Annex C (informative) Sample procedure for assessing applicability and conformance 57 Annex D (informative) Activity limitation issues. 68 Annex E (informative) Access features 74 Annex F (informative) Accessibility and usability 8
21、3 Bibliography . 85 Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 14/01/2010 03:10, Uncontrolled Copy, (c) BSIBS EN ISO 9241-171:2008ISO 9241-171:2008(E) iv ISO 2008 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national st
22、andards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International o
23、rganizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules giv
24、en in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least
25、75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 9241-171 was prepared by Technical Committee ISO/TC 159
26、, Ergonomics, Subcommittee SC 4, Ergonomics of human-system interaction. This first edition of ISO 9241-171 cancels and replaces ISO/TS 16071:2003, of which it constitutes a technical revision. ISO 9241 consists of the following parts, under the general title Ergonomic requirements for office work w
27、ith visual display terminals (VDTs): Part 1: General introduction Part 2: Guidance on task requirements Part 3: Visual display requirements Part 4: Keyboard requirements Part 5: Workstation layout and postural requirements Part 6: Guidance on the work environment Part 7: Requirements for display wit
28、h reflections Part 8: Requirements for displayed colours Part 9: Requirements for non-keyboard input devices Part 11: Guidance on usability Part 12: Presentation of information Part 13: User guidance Part 14: Menu dialogues Part 15: Command dialogues Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STAND
29、ARDS, 14/01/2010 03:10, Uncontrolled Copy, (c) BSIBS EN ISO 9241-171:2008ISO 9241-171:2008(E) ISO 2008 All rights reserved v Part 16: Direct manipulation dialogues Part 17: Form filling dialogues Guidance on software individualization and human-centred design process for interactive systems are to f
30、orm the subjects of future parts 129 and 210. ISO 9241 also consists of the following parts, under the general title Ergonomics of human-system interaction: Part 20: Accessibility guidelines for information/communication technology (ICT) equipment and services Part 110: Dialogue principles Part 151:
31、 Guidance on World Wide Web user interfaces Part 171: Guidance on software accessibility Part 300: Introduction to electronic visual display requirements Part 302: Terminology for electronic visual displays Part 303: Requirements for electronic visual displays Part 304: User performance test methods
32、 Part 305: Optical laboratory test methods for electronic visual displays Part 306: Field assessment methods for electronic visual displays Part 307: Analysis and compliance test methods for electronic visual displays Part 308: Surface-conduction electron-emitter displays (SED) Technical Report Part
33、 309: Organic light-emitting diode (OLED) displays Technical Report Part 400: Principles and requirements for physical input devices Part 410: Design criteria for physical input devices Part 920: Guidance on tactile and haptic interactions Framework for tactile and haptic interaction is to form the
34、subject of a future part 910. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 14/01/2010 03:10, Uncontrolled Copy, (c) BSIBS EN ISO 9241-171:2008ISO 9241-171:2008(E) vi ISO 2008 All rights reservedIntroduction The purpose of this part of ISO 9241 is to provide guidance on the design of the so
35、ftware of interactive systems so that those systems achieve as high a level of accessibility as possible. Designing human-system interactions to increase accessibility promotes increased effectiveness, efficiency and satisfaction for people having a wide variety of capabilities and preferences. Acce
36、ssibility 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 interface are adopting a human-centred approach to design (see ISO 13407), following a context-based design process, providing the ca
37、pacity for individualization (see ISO 9241-110), and offering individualized user instruction and training. It is important to incorporate accessibility goals and features into the design as early as possible, when it is relatively inexpensive compared to the cost of modifying products to make them
38、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 legislative demands for ensuring accessibility by the removal of barriers that prevent people from participating in life activities su
39、ch 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 home, in leisure activities, in public situations and at work. Requirements and/or recommendations are provided for system design, app
40、earance 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 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. Conform
41、ing with the aforementioned International Standard is also important if the goal of accessibility is to be achieved. NOTE 1 While the requirements and recommendations of this part of ISO 9241 are generally applicable to all software application domains, additional detailed guidance on the accessibil
42、ity 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 understanding of the characteristics of individuals who have particular physical, sensory and/or cognitive impairments. However, accessi
43、bility 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, clerks, salespersons, Web designers, etc. The individuals in such target groups vary significantly as regards physical, sensory and co
44、gnitive abilities and each target group will include people with different abilities. Thus, people with disabilities do not form a specific group that can be separated out and then disregarded. The differences in capabilities can arise from a variety of factors that serve to limit the capability to
45、engage in the activities of daily living, and are a “universal human experience” 50. Therefore, accessibility addresses a widely defined group of users including people with physical, sensory and cognitive impairments present at birth or acquired during life, elderly people who can benefit from new
46、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 someone who has forgotten his/her glasses, and people who experience difficulties in particular situations, such as a person who work
47、s in a noisy environment or has both hands occupied by other activities. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 14/01/2010 03:10, Uncontrolled Copy, (c) BSIBS EN ISO 9241-171:2008ISO 9241-171:2008(E) ISO 2008 All rights reserved viiWhen designing and evaluating interactive systems th
48、ere 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, culture, environ
49、ment 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 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 wil
