Bluffers Guide to ISO David Travis

Transcription

1 Bluffers Guide to O 9241 David Travis

2 Bluffers Guide to Usability s, 6th edition Preface About this document First published July 2003 by focus ltd. focus ltd Second edition August Third edition January Fourth edition July Fifth edition November Sixth edition September This document will be updated. To hear about updates, subscribe to the focus mailing list ( About the author David Travis has worked in the areas of psychology, human factors and user interface design for around 20 years. As the UK expert on two O working groups, he has contributed to international usability and ergonomics standards since He has published two books (Effective Colour Displays in 1991 and E- commerce Usability in 2003) and wrote part 6 of DEF-STAN 00-25, a standard created by the UK MOD to provide a single document on human factors issues. He has also contributed to BSI and ANSI national usability standards. He is currently part of a team developing a new O standard on web usability for O TC 159/SC 4/WG5 and is writing an O standard on usability test methods for O TC 159/SC 4/WG2. David can be contacted at david.travis@userfocus.co.uk. About focus focus is a consultancy and training company that helps organisations reduce costs and increase profits by making stuff easier to use. Our clients are typically blue-chip organisations like ebay, RBS and Hewlett Packard who want help improving the usability of their web site, intranet or handheld gadget. Unlike competitor companies, our consultants are experimental psychologists, which means we provide rigorous insights into audience expectations and behaviour. Our techniques will help you:! Increase usage, loyalty and brand value by giving people s that are useful, usable, and desirable.! Identify profitable products and services by systematically analysing the way your customers behave.! Increase productivity and effectiveness by prioritising features and services through actionable prototypes.! Generate rapid ROI and gain quicker time to market by avoiding big changes late in development.! Reduce lifecycle costs by improving communication between development, marketing and contractors.! Reduce litigation risks by helping you meet disability laws and international ergonomics standards. focus ltd 211 Piccadilly London W1J 9HF Tel: ii focus ltd 2007

3 Bluffers Guide to Usability s, 6th edition Table of Contents Preface ii Table of Contents 1 Introduction 2 What is O 9241? 2 Who is O? 2 Other usability standards 3 The parts of O Part 1: introduction 7 Part 2: Guidance on task requirements 8 Part 3: Visual display requirements 9 Part 4: Keyboard requirements 10 Part 5: Workstation layout and postural requirements 11 Part 6: Guidance on the work environment 12 Part 7: Requirements for display with reflections 13 Part 8: Requirements for displayed colours 14 Part 9: Requirements for non-keyboard input devices 15 Part 110: Dialogue principles 16 Part 11: Guidance on usability 17 Part 12: Presentation of information 18 Part 13: 19 Part 14: Menu dialogues 20 Part 15: Command dialogues 21 Part 16: Direct manipulation dialogues 22 Part 17: Form filling dialogues 23 Part 400: Principles and requirements for physical input devices 24 The future parts of O Appendix 1: What it costs 27 Appendix 2: Summary of information 28 Feedback form 29 1 focus ltd 2007

4 Bluffers Guide to Usability s, 6th edition Introduction What is O 9241? In the dusty institutions where usability standards gather to party with each other, O 9241 is a bit of a celebrity. It is widely cited by people who would be hard pushed to name any other standard, and parts of it are virtually enshrined in law in some European countries (such as the UK). But as is the fate of many celebrities, all most usability professionals know about the standard is its name: Ergonomic requirements for office work with visual display terminals (VDTs). Ah, VDTs: as evocative of the eighties as yuppies and punk rock music. This makes the standard seem out of date, but don t be fooled. O have renamed it: as the parts are re-issued they will adopt the much sexier title, The Ergonomics of Human System Interaction. It is a shame that O 9241 is more widely cited than read because it includes a wealth of information that covers every aspect of usability, including hardware, software and usability processes. You could use the standard to design a workstation, evaluate a display, set usability metrics, evaluate a graphical user interface, test out a new keyboard, assess a novel interaction device such as a joystick, check that the working environment is up to scratch, and measure reflections and colour on a display screen. It contains checklists to help structure a usability evaluation, examples of how to operationalise and measure usability, and extensive bibliographies. It even has the courage to define usability! There are a few reasons why it is not widely read.! s are not easy to get hold of. You can t get them in bookshops or find them on the high street (although you can now order them online through O).! O 9241 is expensive. If you purchase all of the parts from O s website ( it will cost SFr.1820 (about 837,!1183 or $1329). Hence the illustration on the front page: standards are big business. (See Appendix 1 for the price of the individual parts.)! The use of the phrase office work in the title of all of the parts of O 9241 makes it sound like the standard is relevant only for, well, office work. In practice, many of the parts are relevant to a wide range of applications. A good example is part 17 (Form Filling dialogues). Although this part was conceived before web sites were common, it contains a lot of that web designers would do well to follow.! s have a reputation for being inaccessible, either because the language is legalistic or because they are written in a peculiar dialect of English that is favoured by people for whom English is not their first language.! O 9241 is big. If you pile all the parts on top of each other it measures over two inches in thickness. This is about as thick as the hardback versions of Nielsen s Usability Engineering and Shneiderman s Designing the Interface combined. (And O 9241 is softback and printed on A4 paper). The truth is that few people would be interested in all of the parts of O 9241, which is why indeed it has been published as separate documents. But it is hard to work out which particular part you are interested in just from the title, and that is about all the information that is publicly available. Also, although you may be interested only in a few of the parts, it s always nice to get an overview and see what you are missing in the other parts. You might choose the standard credit card over the platinum version, but you still like to know about the extras you have forfeited. I hope this document comes to your rescue. View it as your Michelin travel guide to the various destinations of O If nothing else, it will help you bluff your way through a meeting. Who is O? O stands for the Organisation for isation and is a network of national standards institutes from 147 countries. Because technology is an international business, manufacturers pay attention to international standards. Many countries (especially those in Europe) also adopt O standards as national standards, and so you may find parts of O 9241 cited as the route to compliance with health and safety legislation. 2 focus ltd 2007

5 Bluffers Guide to Usability s, 6th edition Other usability standards O 9241 is just one of many standards that apply to usability and ergonomics. Other relevant O usability standards:! O 6385:1981 Ergonomic principles in the design of work systems! O 10075:1991 Ergonomic principles related to mental work-load -- terms and definitions! O :1996 Ergonomic principles related to mental workload -- Part 2: Design principles! O :2000 Ergonomic design of control centres -- Part 1: Principles for the design of control centres! O :2000 Ergonomic design of control centres -- Part 2: Principles for the arrangement of control suites! O :1999 Ergonomic design of control centres -- Part 3: Control room layout! O :1999 Ergonomic requirements for work with visual displays based on flat panels -- Part 1: Introduction! O :2001 Ergonomic requirements for work with visual displays based on flat panels -- Part 2: Ergonomic requirements for flat panel displays! O 13407:1999 Human-centred design processes for interactive systems! O :2002 ergonomics for multimedia user interfaces -- Part 1: Design principles and framework! O :2002 ergonomics for multimedia user interfaces -- Part 3: Media selection and combination! O/TS 16071:2003 Ergonomics of human-system interaction -- Guidance on accessibility for human-computer interfaces! O/TR 16982:2002 Ergonomics of human-system interaction -- Usability methods supporting human-centred design! O/TR 18529:2000 Ergonomics -- Ergonomics of human-system interaction -- Human-centred lifecycle process descriptions! O/IEC :2001 engineering -- Product quality -- Part 1: Quality model! O/IEC TR :2003 engineering -- Product quality -- Part 2: External metrics! O/IEC TR :2003 engineering -- Product quality -- Part 3: Internal metrics! O/IEC :2000, Information technology -- system interfaces and symbols -- Icon symbols and functions -- Part 1: Icons --.! O/IEC :2000, Information technology -- system interfaces and symbols -- Icon symbols and functions -- Part 2: Object icons.! O/IEC 15910:1999 Information technology -- user documentation process This list is far from exhaustive. There are also important national standards, such as BS 7380: 1996 Guide to the design and preparation of on-screen documentation for users of application software and ANSI/NCITS Common Industry Format for Usability Test Reports. Just as each of the parts of O 9241 need to be seen in the context of the whole standard, O 9241 needs to be seen in the context of national and standardisation efforts. 3 focus ltd 2007

6 Bluffers Guide to Usability s, 6th edition The parts of O 9241 To help you choose the part of O 9241 that is of interest to you, I have provided information about each part of the standard on a single page. Each page contains the following information:!!!! Type of Guidance!!!! See also For each part of O 9241, Appendix 2 summarises the lifecycle stage, the type of, and the application area in a single table. In combination with the one-page descriptions of each part, this table should help you choose the parts that are most relevant to you. This section provides the full reference you should use if you want to cite the standard in a document (this is a bluffers guide after all). This section describes the current position of the standard. standards are not born fullyformed but go through a number of gestation stages, shown in Figure 1. Figure 1: The Natural History of an. Documents move from left to right, starting out as an and ending up as an. F Final The terms used in Figure 1 have the following meanings: F. This signals O s intention to produce a standard.. This is an early draft of the standard, for circulation only amongst the experts who are developing it.. The first completed draft, now available for comment (and voting) by national bodies.. The last draft for vote and comment by national bodies. Final. Virtually the final document, pending minor editorial changes (such as punctuation).. In fact, all of the parts of O 9241 are now at stage. The reason I have kept this section in the document is to support later issues of this report, which may also describe standards at earlier stages. Programmers call this upward compatibility. 4 focus ltd 2007

7 Bluffers Guide to Usability s, 6th edition In my book E-commerce Usability 1, I described a development lifecycle model based closely on the usability standard, Human Centred Design processes for Interactive Systems (O 13407: 1999). This model (shown in Figure 2) has four main lifecycle phases:! ;! ;! ;! Track real-world usage and continuously the system. Figure 2: Lifecycle model Opportunity Create the Experience Identify the Stakeholders Write the System Mandate Segment the Market Develop the information architecture Build the Context of Use Agree Key Performance Indicators Layout the screens Build Customer Profiles Build Profiles Build Task Profiles Evaluate usability Track Real-World Usage & Continuously Improve the System We can flesh out this skeleton as follows:! This stage provides the business context for the product or service: within this stage usability professionals identify why the system is being developed, identify the stakeholders and segment the market for the system. They look across platforms and e-channels with a focus on audience behaviour and attitudes.! This results in a rich description of customers, the environment in which customers access the system and a description of realistic activities or scenarios. Usability professionals use these to tease out the inherent psychological aspects of the customer.! This is a rapid, iterative process. Usability professionals begin by agreeing key performance indicators for the system: quantitative measures, based on key customer and business 1 Travis, D. S. (2003) E-Commerce Usability. London: Taylor and Francis. 5 focus ltd 2007

8 Bluffers Guide to Usability s, 6th edition requirements that the management team use to determine if the system is ready to release. Next, they develop the user interface architecture (the high-level, conceptual design) and carry out the detailed design, starting with paper sketches and then moving to electronic slide shows or interactive prototypes. They then test for usability, by using both domain experts and representative customers.! Track real-world usage and continuously the system Usability professionals track customer behaviour as they update their skills, their tasks and their environment. They also track several key business measures to ensure clients get a return on their investment. For each part of O 9241, I use this model to show where the part can be applied in the lifecycle. Some of the parts can be applied at more than one stage. Type of Guidance Some parts of O 9241 contain detailed specifications. For example, O contains the following specification: For character fonts without serifs, the between-character spacing shall be a minimum of one stroke width or one pixel. Other parts contain more general. For example, O contains the following recommendation: If defaults exist for a given task, they should be made available to the user. This section simply identifies the type of contained within the standard. Some parts of O 9241 apply to hardware, some to software and others apply to usability processes. Hardware guidelines are useful for evaluating the ergonomics of workstations. guidelines are useful for detailed on the way user interfaces should look and feel. guidelines are useful for specifying overall quality and usability requirements. This section identifies the application area for the standard. In this section, I provide a detailed description of the contents of the standard. O 9241 is aimed at a range of professional groups, including engineers, usability professionals, designers r interface development tools, end users, and people responsible for procuring software and hardware. However, some of the parts require a certain amount of technical expertise (O on display reflections is a good case in point). Other parts are accessible to anyone. In this section I try to give some idea of the technical skills you will need to fully understand the part. See also The final section contains cross-references to other parts of O 9241 and other standards. 6 focus ltd 2007

9 Bluffers Guide to Usability s, 6th edition Part 1: introduction O :1997 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 1: introduction. F Final This part of O 9241 serves as an introduction to all of the parts in the O 9241 series. It describes the purpose of the 9241 standard and discusses the user performance philosophy. This philosophy is the bedrock of the O 9241 series. s making is a slow process, partly because of the need for consensus and partly because it takes some time for stability to emerge in any new technology. This means that ergonomics standards may not be available to support the procurement of newer interface devices (such as a novel keyboard or a new type of visual display). In such cases, requiring manufacturers to demonstrate evidence of the usability of their products provides the most effective route for ensuring good ergonomics quality. So a number of the parts in the O 9241 series contain user performance tests, to help manufacturers do just that. The standard also includes a bibliography and an informative annex that describes how to apply the software parts of O 9241 (parts 10-17). Under O s plans to renumber O 9241, this part will be replaced by O/TR and O Anyone interested in any part of O See also O 13407:1999 Human-centred design processes for interactive systems. 7 focus ltd 2007

10 Bluffers Guide to Usability s, 6th edition Part 2: Guidance on task requirements O :1992 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 2: Guidance on task requirements. F Final See also This part of O 9241 provides on the design of tasks and jobs that involve work with visual display terminals. It provides on how to identify task requirements and how to specify them within an organisation. It also describes how task requirements can be incorporated into the system design and implementation process. Managers and designers responsible for organising work practices. O 13407:1999 Human-centred design processes for interactive systems. 8 focus ltd 2007

11 Bluffers Guide to Usability s, 6th edition Part 3: Visual display requirements O :1992 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 3: Visual display requirements. F Final This part of O 9241 sets image quality requirements for the design and evaluation of monochrome and colour visual displays. In the UK, the Health and Safety (Display Screen ) Regulations 1992 require displays to be clear, legible and stable under normal working conditions. Displays that meet the requirements in this part of O 9241 are deemed by the Health and Safety Executive to satisfy this design requirement. The requirements in this part of O 9241 are stated as performance specifications and the standard provides test methods and conformance measurements. The specifications cover: design viewing distance; line-of-sight angle; angle of view; character height; stroke width; character width-to-height ratio; raster modulation and fill factor; character format; character size uniformity; between-character spacing; between-word spacing; between-line spacing; linearity; orthogonality; display luminance; luminance contrast; luminance balance; glare; image polarity; luminance uniformity; luminance coding; blink coding; temporal instability (flicker); spatial instability (jittter); and screen image colour. There are four annexes. The first provides analytical techniques for predicting screen flicker. The second describes an empirical method for assessing temporal and spatial instability (flicker and jitter) on screen. The third describes a comparative user performance test method: this annex has since been updated and re-issued as a separate document (O :1992/Amd 1:2000). The final annex is a bibliography. Under O s plans to renumber O 9241, this part will be replaced by the O subseries. See also Manufacturers of visual displays (especially CRT displays) and people that need to evaluate the quality of visual displays. This is a technical standard that requires some knowledge of display design and human vision. O :1992/Amd 1:2000 Visual performance and comfort test. O :1999 Ergonomic requirements for work with visual displays based on flat panels -- Part 1: Introduction. O :2001 Ergonomic requirements for work with visual displays based on flat panels -- Part 2: Ergonomic requirements for flat panel displays. 9 focus ltd 2007

12 Bluffers Guide to Usability s, 6th edition Part 4: Keyboard requirements O :1998 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 4: Keyboard requirements. F Final See also This part of O 9241 provides on the design of keyboards for typical office tasks. The specifications cover the general design of the keyboard and the design of keys. design includes items such as: palm rests; the visible surfaces of the keytops; the slope of the keyboard and keyboard slope adjustment. The design of keys covers items such as: key layout; key displacement and force; keying feedback (such as kinaesthetic feedback); rebound action; key roll-over; key repeat function; key legends; cursor keys; numeric keypad; and keytop shape. The standard specifies the technical measurements that need to be taken to assess compliance, and includes a user performance test for manufacturers of novel keyboards (whose keyboard would otherwise not meet the standard) in an appendix. A second appendix contains a bibliography. Under O s plans to renumber O 9241, this part will be replaced the O subseries. Manufacturers of keyboards and people that need to evaluate the quality of keyboards. O :1998 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 5: Workstation layout and postural requirements. O :2000 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 9: Requirements for non-keyboard input devices. O/IEC 9995:1994 Information processing - Keyboard layouts for text and office systems. 10 focus ltd 2007

13 Bluffers Guide to Usability s, 6th edition Part 5: Workstation layout and postural requirements O :1998 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 5: Workstation layout and postural requirements. F Final See also This part of O 9241 specifies ergonomic guiding principles that apply to the design of workstation equipment used for display screen work. The standard emphasises that the design of the workplace needs to be preceded by an analysis of the tasks that it is intended to support. This information will help identify the different tasks that are carried out and the relative contributions of the different components that support the tasks, which in turn will help users adopt a comfortable and healthy working posture. The specifications are derived from five guiding principles: versatility-flexibility; fit; postural change; user information; and maintainability-adaptability. The specifications themselves cover: posture; ease of adjustment; support surfaces; seating; additional support elements (such as document holders and footrests); and the layout of the workstation in the workspace. An informative annex provides anthropometric data needed for workstation design and selection. Under O s plans to renumber O 9241, this part will be replaced by O Manufacturers of office workstation products and people that need to design and implement office workstations. O :1999 Ergonomic requirements for office work with visual display terminals (VDTS) -- Part 6: Guidance on the work environment. 11 focus ltd 2007

14 Bluffers Guide to Usability s, 6th edition Part 6: Guidance on the work environment O :1999 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 6: Guidance on the work environment. F Final See also This part of O 9241 provides on basic properties of the working environment to support display screen work. The characteristics of the work environment are considered under six headings: natural and artificial lighting (including glare control); sound and noise (including the reduction of noise effects); mechanical vibrations (for example, from air conditioning systems or nearby industrial activities); electromagnetic fields and static electricity (and its effects on the image quality of visual displays); thermal environment (including thermal comfort and humidity); and space organisation and workplace layout. The standard includes four annexes that cover: lighting; methods for measuring and evaluating sound; measurement, evaluation and assessment of whole-body vibrations; and thermal environment (this includes recommended values for thermal comfort). Under O s plans to renumber O 9241, this part will be replaced by O People that need to design and implement office layouts. O :1998 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 5: Workstation layout and postural requirements. 12 focus ltd 2007

15 Bluffers Guide to Usability s, 6th edition Part 7: Requirements for display with reflections O :1998 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 7: Requirements for display with reflections. F Final See also This part of O 9241 aims to help designers measure screen reflections that might affect user comfort and task performance when using display screen equipment. It specifies requirements and methods to measure image quality in lighting environments that can cause specular and diffuse reflections from the screen. The requirements cover: image luminance ratio with reflections; specular reflection luminance ratio; reflection control method and effect on image quality; and the reference luminous environment. The standard includes a detailed section describing how to measure and calculate reflections. The standard also includes four annexes: an alternative, performance-based test method; a graphical report format; a worked example; and a bibliography. Under O s plans to renumber O 9241, this part will be replaced by the O subseries. This is a technical standard that assumes a good working knowledge of light measurement. The main audience is display engineers who want to make sure that anti-reflection treatments do not degrade image quality. O :1992 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 3: Visual display requirements. O :1997 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 8: Requirements for displayed colours. O :2001 Ergonomic requirements for work with visual displays based on flat panels -- Part 2: Ergonomic requirements for flat panel displays. 13 focus ltd 2007

16 Bluffers Guide to Usability s, 6th edition Part 8: Requirements for displayed colours O :1997 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 8: Requirements for displayed colours. F Final See also This part of O 9241 specifies how colour should be used on display screens. It restricts itself to text and graphic applications (photorealistic images are explicitly excluded) but includes both the perceptual and the cognitive aspects of colour. The main guiding principle is that colour should be used to help people correctly perceive, recognise and interpret images and information. The specifications cover: default colour set; colour uniformity; colour misconvergence; character height and object size; colour differences; contrast for symbol and character legibility; spectrally extreme colours; background and surrounding image effects; and number of colours. The standard includes a detailed section on colour measurement from visual displays. There are three annexes: colour difference calculations; a visual performance test (this annex is currently blank, since the test in under development); and a bibliography. In many ways, this part of O 9241 is an elaboration of O , which deals with colour displays only in passing. Under O s plans to renumber O 9241, this part will be replaced by the O subseries. Manufacturers of visual displays (especially CRT displays) and people that develop user interfaces that use colour for coding, formatting and design. Some parts of the standard are technical and assume knowledge of colour measurement. O :1992 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 3: Visual display requirements. O :1998 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 7: Requirements for display with reflections. O :1998 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 12: Presentation of information. O :2001 Ergonomic requirements for work with visual displays based on flat panels -- Part 2: Ergonomic requirements for flat panel displays. 14 focus ltd 2007

17 Bluffers Guide to Usability s, 6th edition Part 9: Requirements for non-keyboard input devices O :2000 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 9: Requirements for non-keyboard input devices. F Final See also This part of O 9241 applies to several types of non-keyboard input devices including mice, pucks, joysticks, trackballs, tablets and overlays, touch-sensitive screens, styli and light pens. The standard specifies the quality of the input device in terms of a performance criterion: it is considered useable [sic] if users can achieve a satisfactory level of performance on a given task and maintain an acceptable level of effort and satisfaction. The standard also includes a set of design requirements that first covers general requirements and (such as resolution, button design and upper extremity and head posture), and then addresses specific input device requirements and (such as mice, pucks and joysticks). Compliance with the standard can be achieved only by carrying out a usability test. The standard has four annexes: input device selection, usability and analysis; of efficiency and effectiveness; assessment of comfort; and additional evaluation methods. The standard also includes a bibliography with over 100 references. Note that this standard does not cover voice input. Under O s plans to renumber O 9241, this part will be replaced by the O subseries. Manufacturers of non-keyboard input devices and people that need to evaluate these devices. O :1998 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 4: Keyboard requirements. 15 focus ltd 2007

18 Bluffers Guide to Usability s, 6th edition Part 110: Dialogue principles O :2006 Ergonomics of human-system interaction -- Part 110: Dialogue principles. F Final See also This part of O 9241 presents a set of usability heuristics that applies to the interaction of people and information systems (the heuristics are based on an earlier German standard). The standard refers to this interaction as a dialogue and describes seven dialogue principles. These general principles span the specific dialogue techniques that are discussed in parts of O The seven principles are: suitability for the task (the dialogue should be suitable for the user s task and skill level); self-descriptiveness (the dialogue should make it clear what the user should do next); controllability (the user should be able to control the pace and sequence of the interaction); conformity with user expectations (it should be consistent); error tolerance (the dialogue should be forgiving); suitability for individualisation (the dialogue should be able to be customised to suit the user); and suitability for learning (the dialogue should support learning). The standard describes applications and examples of the dialogue principles. It has one annex (a short bibliography). This part of O 9241 used to be known as O 9241 part 10, but has now been renumbered under O's revision and restructuring programme. interface designers and evaluators. O :1998 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 12: Presentation of information. O :1998 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 13:. O :1997 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 14: Menu dialogues. O :1997 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 15: Command dialogues. O :1999 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 16: Direct manipulation dialogues. O :1998 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 17: Form filling dialogues. 16 focus ltd 2007

19 Bluffers Guide to Usability s, 6th edition Part 11: Guidance on usability O :1998 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 11: Guidance on usability. F Final See also This part of O 9241 introduces the concept of usability but does not make specific in terms of product attributes. Instead it 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. One of the benefits of this approach is that it helps design teams plan for usability as part of the development lifecycle, by setting and measuring usability goals for the product. The standard describes how it can be applied to: specify and measure the usability of products; specify and evaluate usability during design; and specify and measure a work system in use. The standard includes five annexes: an example of how to specify the context of use; examples of usability measures; an example of a usability requirements specification; relationship to other international standards; and a bibliography. The term satisfaction in the definition of usability has been criticised as sounding weak: it sounds like adequate or just good enough, which is hardly a design goal worthy of aspiration. However, this is more an artefact of current usage: the dictionary defines satisfaction as the feeling of pleasure that comes when a need or desire is fulfilled. Anyone that needs to set or measure usability goals for a system. O 13407:1999 Human-centred design processes for interactive systems. O/IEC :2001 engineering -- Product quality -- Part 1: Quality model. O/IEC TR :2003 engineering -- Product quality -- Part 2: External metrics. O/IEC TR :2003 engineering -- Product quality -- Part 3: Internal metrics. 17 focus ltd 2007

20 Bluffers Guide to Usability s, 6th edition Part 12: Presentation of information O :1998 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 12: Presentation of information. F Final See also This part of O 9241 contains on how to present visual information on screens so that users can easily perform perceptual tasks (such as searching for information on the screen). The are based on seven guiding principles: clarity (information should be conveyed quickly and accurately); discriminabilty (information should be able to be distinguished accurately); conciseness (provide only the information necessary to complete the task); consistency (present the same information in the same way throughout the application); detectability (direct the user s attention to the information required); legibility (information should be easy to read); and comprehensibility (the meaning should be clearly understandable). The are provided in three main areas: organisation of information; graphical objects; and coding techniques. There is no discussion of icon design in this standard. The standard has two annexes. The first is a sample procedure for assessing applicability and adherence and includes a detailed design checklist spanning 13 pages. This compliance procedure is based on the notion of conditional compliance : the assessor first determines which are relevant and then determines whether or not they have been adhered to. The reason for this approach is that users, tasks and technological solutions vary and it is therefore not possible to give blanket that apply to all systems that present visual information. The conditional compliance route is O s acknowledgement of this variability and complexity. The second annex is a bibliography. Under O s plans to renumber O 9241, this part will be replaced by replaced by O and O interface designers and evaluators. O :1997 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 8: Requirements for displayed colours. O :2006 Ergonomics of human-system interaction -- Part 110: Dialogue principles. O/IEC :2000 Information technology -- system interfaces and symbols -- Icon symbols and functions -- Part 1: Icons --. O/IEC :2000 Information technology -- system interfaces and symbols -- Icon symbols and functions -- Part 2: Object icons. 18 focus ltd 2007

21 Bluffers Guide to Usability s, 6th edition Part 13: O :1998 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 13:. F Final This part of O 9241 contains on user. The cover general advice; prompts; feedback; status information; error management; and on-line help. This standard does not cover documentation (either on-line or paper) or on-line tutorials. The standard contains two annexes. The first is a sample procedure for assessing applicability and adherence and includes a six-page checklist (using a conditional compliance route, see the description of O ). The second annex is a bibliography. Under O s plans to renumber O 9241, this part will be replaced by O interface designers, user interface evaluators and documentation experts. See also O :2006 Ergonomics of human-system interaction -- Part 110: Dialogue principles. O/IEC 6592:2000 Information technology -- Guidelines for the documentation of computer-based application systems. O/IEC 15910:1999 Information technology -- user documentation process. BS 7649: 1993 Guide to the design and preparation of documentation for users of application software. BS 7380: 1996 Guide to the design and preparation of on-screen documentation for users of application software. 19 focus ltd 2007

22 Bluffers Guide to Usability s, 6th edition Part 14: Menu dialogues O :1997 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 14: Menu dialogues. F Final This part of O 9241 provides for the design of systems that use menus (such as pop-up, pull-down and text-based menus). The standard begins by reviewing the application areas where menus are most useful (for example, when use of the system is infrequent and the user does not know what options are available). The cover: menu structure (such as logical categories, grouping options and ordering items); menu navigation (including titles and access time); option selection and execution (including selection methods, use of the keyboard and voice activation); menu presentation (including placement and use of icons). The standard contains three annexes. The first is a sample procedure for assessing applicability and adherence and includes a ten-page checklist (using a conditional compliance route, see the description of O ). The second annex provides three scenarios of how to apply the standard (from the perspective of the user interface designer, the procurer and the evaluator). The third annex is a detailed bibliography. Under O s plans to renumber O 9241, this part will be replaced by O interface designers and evaluators. See also O :2006 Ergonomics of human-system interaction -- Part 110: Dialogue principles. 20 focus ltd 2007

23 Bluffers Guide to Usability s, 6th edition Part 15: Command dialogues O :1997 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 15: Command dialogues. F Final This part of O 9241 provides for systems that use command line interfaces (such as DOS and UNIX). With a command line interface, the user works with the system by typing in commands that meet certain syntactic rules. The standard begins by describing the appropriate application areas for these interfaces (for example, applications that people use frequently, and that require speed and flexibility). The cover: structure and syntax (for example, macros and command arguments); command representation (for example, command names and abbreviations); input and output considerations (for example, command reuse and editing); and feedback and help (for example, command processing and error feedback). The standard contains two annexes. The first is a sample procedure for assessing applicability and adherence and includes a five-page checklist (using a conditional compliance route, see the description of O ). The second annex is a bibliography. Under O s plans to renumber O 9241, this part will be replaced by O interface designers and evaluators. See also O :2006 Ergonomics of human-system interaction -- Part 110: Dialogue principles. 21 focus ltd 2007

24 Bluffers Guide to Usability s, 6th edition Part 16: Direct manipulation dialogues O :1999 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 16: Direct manipulation dialogues. F Final This part of O 9241 provides for systems that use direct manipulation (such as Windows and Macintosh). With direct manipulation, the user acts directly on the objects on the screen (for example by dragging a document icon and dropping it on an application to open it). The standard points out that this is not the same as a graphical user interface, which may or may not implement direct manipulation. The standard begins by describing the appropriate application areas for these interfaces (for example, the system can simulate real-world task objects, their properties and operations). The cover: general information (metaphors; the appearance of objects used in direct manipulation; feedback; and input devices); manipulation of objects (general considerations; pointing and selecting; dragging; sizing of objects; and rotating); direct manipulation of text objects (pointing and selecting; and sizing of text); direct manipulation of windows (general considerations; pointing and selecting; and sizing of windows); and direct manipulation of control icons (pointing and selecting). The standard contains one annex and a bibliography. The annex is a sample procedure for assessing applicability and adherence and includes a three-page checklist (using a conditional compliance route, see the description of O ). Under O s plans to renumber O 9241, this part will be replaced by O interface designers and evaluators. See also O :2006 Ergonomics of human-system interaction -- Part 110: Dialogue principles. O :1997 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 14: Menu dialogues. O :1998 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 17: Form filling dialogues. 22 focus ltd 2007

25 Bluffers Guide to Usability s, 6th edition Part 17: Form filling dialogues O :1998 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 17: Form filling dialogues. F Final This part of O 9241 provides for systems that use form filling interfaces (now commonly seen on the web). With form filling (or fill in the blanks ) interfaces, users see a display of related fields and enter data where required. The standard begins by describing the appropriate application areas for these interfaces (for example, when users have with paper forms but limited with computers). The cover form filling structure, input considerations, feedback and navigation. Form filling structure covers: general; layout; and fields and labels. Input considerations covers: general; alphanumeric text entry; choice entries; control; and field validation. Feedback covers: echoing; cursor and pointer position; field errors; transmission acknowledgement; and database changes. Navigation covers: initial cursor position; movement between fields; return to initial field; tabbing; scrolling; and form selection. The standard contains two annexes. The first is a sample procedure for assessing applicability and adherence and includes a nine-page checklist (using a conditional compliance route, see the description of O ). The second annex is a bibliography and contains a table cross-referencing the in the standard to the academic sources. Under O s plans to renumber O 9241, this part will be replaced by O interface designers and evaluators. See also O :2006 Ergonomics of human-system interaction -- Part 110: Dialogue principles. 23 focus ltd 2007

26 Bluffers Guide to Usability s, 6th edition Part 400: Principles and requirements for physical input devices O :2007 Ergonomics of human-system interaction -- Part 400: Principles and requirements for physical input devices. F Final This part of O 9241 describes generic ergonomic principles for the design and use of input devices, such as keyboards, mice and joysticks. It does not provide specific design for these devices, but instead provides a background in the important ergonomic requirements that designers need to consider. The whole of the 400 series will be devoted to input devices and this part is really the introduction to the series (the other parts in the series are listed in the next section, The future parts of O 9241 ). There are three key sections: (a) definitions, (b) design requirements and (c) properties of input devices relevant for usability. The bulk of the standard (around 40% of the page count) is devoted to various definitions, from click through to ulnar deviation. (In case you were wondering, a click is the depression and release of a button or actuation point on an input device ). The design guidelines are Appropriateness (the input device should match the user, the user s tasks and the user s work environment); Operability (its intended use should be obvious, predictable and consistent); Predictability (it should match user expectations); Consistency (it should behave in the same manner when used in similar situations); compatibility (the design should match the anthropometric and biomechanical capabilities rs); Feedback (the device should let the user know when it is responding to the user s actions); Controllability (the device should be responsive); and Biomechanical load (which should be minimised). The properties of input devices relevant for usability include functional properties (such as keyboard slope); electrical properties (such as the thickness of cabling for a mouse); mechanical properties (such as the weight of a handheld device); and interdependency with software. See also Manufacturers of input devices and people that need to evaluate the quality of input devices. It is unlikely that anyone would read this part in isolation: it makes sense only as an introduction to the other parts in the 400 series. O :1998 Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 4: Keyboard requirements. 24 focus ltd 2007

27 Bluffers Guide to Usability s, 6th edition The future parts of O 9241 O is carrying out a major revision and restructuring of the O 9241 standard to incorporate other relevant standards. O is also renaming the standard to The ergonomics of human system interaction. The table below shows the title and the current status of the parts (as at September 2007). Part Title 20 Accessibility guidelines for information / Under preparation communication technology (ICT) equipment and services 100 Introduction to software ergonomics Planned 111 Presentation principles Planned to partially revise and replace O Multimedia principles Planned to revise and replace O GUI and controls principles Planned 121 Presentation of information Planned 122 Media selection and combination Planned to revise and replace O Navigation Planned to partially revise and replace O Planned to revise and replace O Individualization Planned 130 Selection and combination of dialogue techniques Planned to incorporate and replace O :1997/Amd 1: Menu dialogues Planned to replace O Command dialogues Planned to replace O Direct manipulation dialogues Planned to replace O Form based dialogues Planned to replace O Natural language dialogues Planned 141 Controlling groups of information (including Planned to partially replace O windows) 142 Lists Planned 143 Media controls Planned to partially revise and replace O Guidance on World Wide Web software user Under preparation interfaces 152 Interpersonal communication Planned 153 Virtual reality Planned 171 Guidance on software accessibility Under preparation 200 Introduction to human centred design Planned standards 210 Human centred design of interactive systems Planned to revise and replace O Human-centred lifecycle processes Planned to revise and replace O/PAS Human-centred design methods Planned to revise and replace O/TR Introduction to requirements and Under preparation measurement techniques for electronic visual displays 302 Terminology for electronic visual displays Under preparation 303 Requirements for electronic visual displays Under preparation 304 performance test methods Under preparation 305 Optical laboratory test methods for electronic Under preparation visual displays 306 Field assessment methods for electronic visual Under preparation displays 307 Analysis and compliance test methods for electronic visual displays Under preparation 25 focus ltd 2007