Ergonomics User Interface Standards

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Ergonomics user interface standards: are they more trouble than they are worth?
Tom Stewart System Concepts Limited 2 Savoy Court, Strand London WC2R 0EZ Tel: +44 207 240 3388 Fax: +44 207 240 5212 Email: [email protected]

Note: This paper was originally written for HFES2000 and published in Ergonomics. Taylor & Francis retain copyright but have granted permission for this article to be distributed from System Concepts’ website. This document can be found at the following URL: http://www.system-concepts.com/stds/standards.pdf ©Taylor & Francis 2000. http://www.tandf.co.uk/journals

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Abstract
The purpose of this paper is to review the history, progress and results of one area of international standardisation – the ergonomics of human-system interaction. It is a personal perspective based on my experiences as Chairman of ISO/TC159/SC4 over the past seventeen years. The paper starts with some historical background and summarises the main work of the committee. It then identifies five areas where the results of the standardisation work could have been more successful and discusses what went wrong. These problems include the long timescale for development, how the standards were misunderstood, how political the process can be, how we may have tried to be too clever and how the abundance of help at times may have been a problem. But the paper concludes with an explanation of why the activity and the results were not all bad. The five positive areas include the benefits which can come from the slow pace, the benefits of structure and formality, why standards do not have to be restrictive, how the standards themselves are only part of the outcome and how being a truly international experience makes it all worth while.

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1. Introduction
The purpose of this paper is to review the history, progress and results of one area of international standardisation – the ergonomics of human-system interaction - over the past seventeen years. Although I will attempt to put the case for and the case against standards, it would be foolish for me to suggest that this will be an impartial review. I would not have spent and continue to spend a significant portion of my working life developing standards if I were not basically convinced that the effort was worthwhile. Nonetheless, I would argue that although many people criticise standards (sometimes correctly), no-one is more aware of the shortcomings of the process (and the end results) than those who struggle to make it work. I am therefore delighted to have been given the opportunity by the Human Factors and Ergonomics Society and the International Ergonomics Association to stand back and take another look at our standardisation work. Of course, I have said much of this before in various forms and to different audiences (for example Stewart 1998, Stewart 1999). Anyone who read or attended these earlier sessions will be familiar with some of the arguments – it is difficult to find new ways to describe the same issues and the same standards – nonetheless this is a major opportunity to pull it all together and give a more considered overview. However, before progressing, I would like to make it clear which standardisation activities I am reviewing – there are more than you might suspect. 1.1 Standards are such fun everyone wants one of their own In most people’s minds, one of the most basic and fundamental objectives of standardisation is to minimise unnecessary variations. Ideally, for any product category, there is one standard which should be satisfied and products which meet that standard give their owners or users some reassurance about quality or about what standards makers refer to as interoperability. Thus yachtsmen in Europe who buy a lifejacket which meets EN 396 might reasonably expect it to keep them afloat if they have the misfortune to fall overboard. Similarly, an office manager in the USA who orders A4 paper for their photocopiers (ISO 216:1975) might reasonably expect paper which meets that standard to fit even though it is not the typical size used locally. Which brings us to a rather important point. It is often difficult to achieve a single agreed standard and a common solution is to have more than one standard. An obvious example concerns paper size where there are the ISO A series (A0, A1 etc), the ISO B series (B0, B1 etc) as well as US sizes (legal, letter etc). Although this solves the standards makers problems in agreeing a single standard, it is an endless source of frustration for users of the standard as anyone who has forgotten to check the paper source in an emailed document can testify. However, there is another reason why there are more standards than one might imagine, especially when it comes to user interface design issues. The reason is that computer technology forms the basis of many different industries and standards can have an important impact on market success. Even in my corner of the standardisation world (ISO/TC 159/SC4 Ergonomics of Human System Interaction), I have enjoyed collaboration with a number of usability standards bodies including:

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ISO/IEC JTC1/SC35 Cultural and linguistic adaptability (was SC18/WG9 User system interfaces and symbols) § ETSI/TC-HF § IEEE P1201.2 User Interface Drivability § ECMA TC 35 User System Interface § CEN/TC122/WG5 Ergonomics of VDTs It is not just at the international level that there appears to be some duplication. In the UK, the British Standards Institution mirror committee to SC4 published an early version of the first six parts of ISO 9241 as a British Standard BS 7179: 1990. The prime reason for this was to provide early guidance for employers of users of visual displays who wanted to use standards to help them select equipment which met the requirements in the Schedule to the Health and Safety (Display Screen Equipment) Regulations 1992. These regulations are the UK implementation of a European Community Directive on the minimum safety and health requirements for work with display screen equipment (90/270/EEC). Of course, as a spin-off the British Standards Institution were able to generate revenue from selling these standards several years before the various parts of ISO 9241 became available as British Standards. A similar process has taken place in the US with the Human Factors and Ergonomics Society (HFES) developing HFS 100 on Visual Display Terminal Ergonomics as an ANSIauthorised Standards Developing Organisation. More recently there are two HFES standards development committees working on HFES 100 (a new version of HFS 100) and on HFES 200 which addresses user interface issues. It includes sections on accessibility, voice and telephony applications, colour and presentation, and slightly re-written parts of the software parts of ISO 9241. Although in this paper, I will focus solely on the work the ISO/TC159/SC4 The Ergonomics of Human System Interaction, many of the comments are relevant to other standards activities. 1.2 How the International Organisation for Standardisation works The International Organisation for Standardisation (ISO) comprises national standards bodies from member states. (see www.iso.ch for more information). Its work is conducted by technical and sub-committees which meet every year or so and are attended by formal delegations from participating members of that committee. In practice, the technical work takes place in Working Groups of experts, nominated by national standards committees but expected to act as independent experts. The standards are developed over a period of several years and in the early stages, the published documents may change dramatically from version to version until consensus is reached (usually within a Working Group of experts). As the standard becomes more mature (from the Committee Draft Stage onwards), formal voting takes place (usually within the parent sub-committee) and the draft documents provide a good indication of what the final standard is likely to look like. Table 1 shows the main stages. §

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Table 1. WI The main stages of ISO standards development.

Work Item--an approved and recognised topic for a working group to be addressing which should lead to one or more published standards. WD Working Draft--a partial or complete first draft of the text of the proposed standard. CD Committee Draft--a document circulated for comment and approval within the committee working on it and the national mirror committees. Voting and approval is required for the document to reach the next stage. DIS Draft International Standard--a draft standard which is circulated widely for public comment via national standards bodies. Voting and approval is required for the draft to reach the final stage. FDIS Final Draft International Standard--the final draft is circulated for formal voting for adoption as an International Standard. IS International Standard. The final published standard. Note: Documents may be reissued as further CDs and DISs 1.3 How this paper is structured In section 2, I describe the origins of ISO/TC159/SC4 and the work which has led to its main standards published today, primarily the ISO 9241 series. Next, in section 3, I explain how we thought ISO 9241 would be used to support system design decisions. Then, in section 4, I review all the problems and issues which have led some to believe standards are just too much trouble. In section 5, I argue that the benefits of the standards and, in some ways more importantly, the standardisation process outweigh these admitted disadvantages. Finally, I outline how this area of standards work might develop in the future.

2.

The origins of ISO/TC159/SC4

In the late 1970s, there was growing concern about the ergonomics of visual display terminals (also called visual display units). The prime concern at that time concerned the possibility that prolonged use (especially of displays with poor image quality) might cause deterioration in users eyesight. (note: Since then several studies have shown that ageing causes the main effect on eyesight and since display screen work can be visually demanding, many people only discover this deterioration when they experience discomfort from intensive display screen use. This can incorrectly lead them to attribute their need for glasses to their use of display screens.) When a new work item to address this concern was proposed, the Information Technology committee decided that this was a suitable topic for the recently formed ergonomics committee ISO/TC 159. The work item was allocated to the sub-committee ISO/TC 159/SC4 Signals and Controls and an inaugral meeting was held at BSI in Manchester in 1983. The meeting was well attended with delegates from many countries and a few key decisions were made. At that time, there was a proliferation of office based systems and we decided to focus on office tasks (word processing, spreadsheet etc) rather than try to include Computer Aided
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Design or process control applications. We also decided that we would need a multi-part standard to cover the wide range of ergonomics issues which we believed needed to be addressed in order to improve the ergonomics of display screen work. Six initial parts were identified and working groups established (see Table 2). At the end of that first meeting, one of the distinguished participants, Professor Bengt Knave from Sweden was heard to complain that we had been meeting for three days and still had not standardised anything. Little did any of us realise that it would be nearly seven years before the first parts of ISO 9241 would be published and that it would take us to the end of the century to publish all seventeen parts. Table 3 shows the seventeen parts of ISO 9241 Ergonomic requirements for office work with visual display terminals (VDTs). Table 2. WG1. WG2. WG3. WG4. WG5. WG6. WG8. Table 3. Working Groups of ISO/TC159/SC4 Fundamentals of controls and signalling methods Visual display requirements Control, workplace and environmental requirements Task requirements (disbanded) Software ergonomics and human-computer dialogue Human-centred design processes for interactive systems Ergonomics design of control centres Parts and Status of ISO 9241 Responsible Working Group WG6 WG4 (finished) WG2 WG3 WG3 WG3 WG2 WG2 WG3 WG5 WG5 WG5 WG5 WG5 WG5 WG5 WG5 Status Dec 1999 IS IS IS IS IS IS IS IS FDIS IS IS IS IS IS IS IS IS

ISO 9241 Ergonomic requirements for office work with visual display terminals (VDTs) Part1 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 displays with reflections Part 8 Requirements for displayed colours Part 9 Requirements for non-keyboard input devices Part 10 Dialogue principles Part 11 Guidance on usability Part 12 Presentation of information Part 13 User guidance Part 14 Menu dialogues Part 15 Command dialogues Part 16 Direct manipulation dialogues Part 17 Form filling dialogues

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Table 4 shows the other human system interaction standards for which ISO/TC 159/SC4 is responsible. Table 4. Other human system interaction standards for which ISO/TC 159/SC4 is responsible ISO Standards Responsible Working Group WG2 WG2 WG5 WG5 WG5 WG5 WG5 WG6 WG6 WG6 WG8 WG8 WG8 WG8 WG8 WG8 WG8 WG8 Status Dec 1999 IS FDIS DIS 2nd CD DIS WI WD IS CD TR FDIS FDIS IS WD WD WD WI WI

13406-1 13406-2 14915-1 14915-2 14915-3 14915-4 TS 16071 13407 TS 16982 TR 18529 11064-1 11064-2 11064-3 11064-4 11064-5 11064-6 11064-7 11064-8

Ergonomics requirements for flat panel displays - Introduction Ergonomics requirements for flat panel displays – Ergonomics requirements Software ergonomics for multi-media interfaces – Design principles and framework Multimedia control and navigation Media selection and combination Domain-specific multimedia aspects Accessibility Human centred design processes for interactive systems Usability methods supporting HC design Human centred lifecycle process descriptions Principles for the design of control centres Principles of control suite arrangement Control room layout Workstation layout and dimensions Displays and controls Environmental requirements for control rooms Principles for the evaluation of control centres Ergonomics requirements for specific applications

3.

How we intended ISO 9241 to be used

The structure of the standard was decided at a time when there were clear distinctions between hardware and software and monochrome Cathode Ray Tube (CRT) displays were the norm. The first six parts were therefore primarily concerned with hardware (which, in our naivete we thought would be easier and less contentious to standardise). However, even within this hardware domain, we recognised the importance of job and task design in ensuring that users could work safely, comfortably and efficiently – so part 2 was inserted before the more technical hardware oriented parts.

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Later, software parts (10 to 17) were added, reflecting the different styles of user system interaction which were available at the time and additional hardware parts were added to deal with reflections (7), colour displays (8) and non-keyboard input devices, eg mouse (9). The structure therefore reflected the practicalities and history of standard making and unfortunately is not very user-centred (one of the key principles of ergonomics). Although we did not make it explicit at the time, we had an underlying set of assumptions about human-computer interaction (HCI) design activities and how the standards would support these. These activities included: • Analysing and defining system requirements • Designing user-system dialogues and interface navigation • Designing or selecting displays • Designing or selecting keyboards and other input devices • Designing workplaces for display screen users • Supporting and training users • Designing jobs and tasks Table 5 (at the end of this document) shows how we anticipated the standards being used.

4.

So what went wrong?

Looking back, I believe that there were a number of things which went wrong or perhaps, more accurately, did not quite go according to plan. It has been pointed out that hindsight has 20/20 vision. Maybe we could have anticipated more of the problems, but I am not certain that anyone really understood the implications of what we were doing. Certainly, until that time, much standardisation work had dealt with far more limited scopes and much more established technologies. For example, there is an entire Technical Committee which specialises in ‘Light gauge metal containers’ (TC52). Our sub-committee was attempting to address all the ergonomics issues associated with interactive systems. Nonetheless, I believe there were 5 main areas where it could have been better: § It took much longer than we thought § We and our standards were misunderstood § We did not appreciate how political it was or would get § We tried to be too clever § We had too much help at times I explain these points in more detail below: 4.1 It took much longer than we thought The disappointment of one delegate at the meeting in Manchester has already been mentioned but none of us appreciated just how long the process would take. One of the reasons why the process is slow is that there is an extensive consultation period at each stage of development with time being allowed for national member bodies to circulate the documents to mirror committees and then to collate their comments. Another reason is that Working Group members can spend a great deal of time working on drafts and reaching consensus only to find that the national mirror committees
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reject their work when it comes to the official vote. It is particularly frustrating for project editors to receive extensive comments (which must be answered) from countries who do not send experts to participate in the work. Of course, the fact that the work is usually voluntary means that it is difficult to get people to agree to work quickly. 4.2 We and our standards were misunderstood While I do not accept that we have produced bad standards (at least in our committee), our standards have been criticised for being too generous to manufacturers in some areas and too restrictive in other areas. The ‘over-generous’ criticism misses the point that most standards are setting minimum requirements and in ergonomics we must be very cautious about setting such levels. However, there certainly are areas where being too restrictive is a problem. Examples include: § ISO 9241-3:1992 Ergonomics requirements for work with VDTs: Display Requirements. This standard has been successful in setting a minimum standard for display screens which has helped purchasers and manufacturers. However, it is biased towards Cathode Ray Tube (CRT) display technology. An alternative method of compliance based on a performance test (which would be technology independent) is still under development but has just (December 1999) been approved as a Draft International Standard and should therefore be finalised in the near future. § ISO FDIS 9241-9:1999 Ergonomics requirements for work with VDTs: Non keyboard input devices. This standard has suffered because technological developments were faster than either ergonomics research or standards making. Although there has been an urgent need for a standard to help users to be confident in the ergonomic claims made for new designs of mice and other input devices, the lack of reliable data forced the standards makers to slow down or run the risk of prohibiting newer, even better solutions. The biggest area of misunderstanding is that some people seem surprised to discover that user interface standards not only do not solve all the problems in user interface design, but they do not even address some of the most difficult parts of design. I am really not sure where this misunderstanding arose. Even though we, in the standards community, believe that standards are part of the solution, I do not know anyone who believes they are the whole story or thinks they should be. Elizabeth Buie (1999) has published an excellent review of such problems and explains why how standards fit into the overall picture. 4.3 We did not appreciate how political it was or would get Although ergonomics standards are generally concerned with such mundane topics as keyboard design or menu structures, they nonetheless generate considerable emotion amongst standards makers. Sometimes this is because the resulting standard could have a major impact on product sales or legal liabilities. Other times the reason for the passion is less clear. Nonetheless, the strong feelings have resulted in painful experiences in the process of standardisation, especially for me as committee chairman. These have included: § Undue influence of major players- Large multinational companies can try to exert undue influence by dominating national committees. Although draft standards are usually publicly available from national standards bodies, they are not widely publicised. This means that it is relatively easy for well informed large companies to provide sufficient
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experts at the national level to ensure that they can virtually dictate the final vote and comments from a country. § ‘Horse trading’ and bargaining to achieve agreement - End user’s requirements can be compromised as part of ‘horse trading’ between conflicting viewpoints. In the interests of reaching agreement, delegates may resort to making political trade-offs largely independent of the technical merits of the issue. Uncritical support for favourite ideas- National pride can lead to uncritical support for a particular approach or methodology. In theory, participants in Working Group meetings are experts nominated by member bodies in the different countries. They are not there to represent a national viewpoint but are supposed to act as individuals. However, as one disillusioned expert explained to me ‘sometimes the loudest noise at a Working Group meeting is the grinding of axes’.

§

4.4 We tried to be too clever One of the criticisms we face as ergonomics and human factors specialists is that we generally spend too much time talking to ourselves. I am not referring to some abnormal mental state of delusion but rather the tendency amongst all experts to be more interested in the views of their fellows than in addressing the wider public. The same criticism can be levelled at standards makers. Indeed in ISO the formal rules and procedures for operating seem to encourage an elitist atmosphere with standards written for standards enthusiasts. ISO has recognised this and is attempting to make the process more customer focussed but such changes take time. Within our committees, these procedures and rules have reinforced our elitist tendencies and sometimes resulted in standards which leave much to be desired in terms of brevity, clarity and usability. There are three contributory factors: 1. The use of stilted language and boring formats. The unfriendliness of the language is illustrated by the fact that although the organisation is known by the acronym ISO, its full English title is the International Organisation for Standardisation. The language and style are governed by a set of Directives and these encourage a wordy and impersonal style. 2. Problems with translation and the use of ‘Near English’. There are three official languages in ISO - English, French and Russian. In practice, much of the work is conducted in English, often by non-native speakers. As someone who only speaks English, I have the utmost respect for those who can work in more than one language. However, the result of this is that the English used in standards is often not quite correct - it is ‘near English’. The words are usually correct but the combination often makes the exact meaning unclear. These problems are exacerbated when the text is translated. 3. Confusions between requirements and recommendations. In ISO standards, there are usually some parts which specify what has to be done to conform to the standard. These are indicated by the use of the word ‘shall’. However, in ergonomics standards, we often want to make recommendations as well. These are indicated by the use of the word ‘should’. Such subtleties are often lost on readers of standards, especially those in different
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countries. For example, in the Nordic countries, they follow recommendations (shoulds) as well as requirements (shalls), so the distinction is diminished. In the USA, they tend to ignore the ‘shoulds’ and only act on the ‘shalls’. 4.5 We had too much help at times This might sound like an unlikely problem but given the long timescale mentioned above it can be a significant factor in slowing down the process. The reason is that many experts are only supported by their organisations for a relatively short time and are then replaced by other experts. Every time a new expert joins the Working Group, there is a tendency to spend a lot of time explaining the history and to some extent starting the process again. Similarly, each expert feels obliged to make an impact and suggest some enhancement or change in the standard under development. Since the membership of Working Groups can change at virtually every meeting (which are usually three or four months apart), it is not uncommon for long standing members to find themselves reinstating material which was deleted two or three meetings previously (as a result of a particularly forceful individual).

5.

But it was not all bad

As I mentioned right at the beginning of this paper, neither my colleagues in standardisation nor I would spend so much time and effort if we did not believe the results would be worthwhile. Looking back, some things really worked well and in mitigation of the criticisms, I would argue the following: § Slower is not necessarily worse § Structure and formality can be a help as well as a hindrance § Standards do not have to be unduly restrictive § The benefits do not just come from the standards themselves § Being international makes it all worthwhile I argue these points in more detail below: 5.1 Slower is not necessarily worse Standards making is painfully slow. I am not suggesting that this is good, especially in such a fast moving area as user interface design. However, there are some benefits which come directly from the pace of the process, in addition to the widespread consultation which I have already mentioned. One benefit is that when the technology is moving quicker than the standards makers can react, it does make it clear that certain types of standards may be premature. For example, ISO 9241-14:1997 Menu Dialogues was originally proposed when character-based menu driven systems were a popular style of dialogue design. Its development was delayed considerably for all manner of reasons (many beyond our control). But these delays meant that the final standard was relevant to pull down and pop-up menus which had not even been considered when the standard was first proposed. Another benefit is that during the development process, those who may be affected have the opportunity to prepare for the standard. Thus by the time ISO 9241-3:1992 Display requirements was published, many manufacturers were able to claim that they already produced monitors which met the standard. They had not been in that position when
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the standard was first proposed and although they might like to argue that they would have been improving the design of their displays anyway, I am not convinced that is entirely true. Certainly the standards provided a clear target for both demanding consumers and quality manufacturers. 5.2 Structure and formality can be a help as well as a hindrance One of the benefits of standards is that they do represent a rather simplified and structured view of the world. There is also a degree (sometime excessive) of discipline in what a standard can contain and how certain topics can be addressed. Manufacturers (and ergonomists) frequently make wildly different claims about what represents good ergonomics. This is a major weakness for our customers who may conclude that all claims are equally valid and there is no sound basis for any of it. Standards force a consensus and therefore have real authority in the minds of our customers. Achieving consensus requires compromises, but then so does life. The formality of the standards mean that they are suitable for inclusion in formal procurement processes and for demonstrating best practice. In the UK at least, parts of ISO 9241 may be used by suppliers to convince their customers that visual display screen equipment and its accessories meet good ergonomic practice. Of course, they can also be ‘abused’ in this way with over-eager salesmen misrepresenting the legal status of standards but that is hardly the fault of the standards makers. 5.3 Standards do not have to be unduly restrictive I have already described the problem we experienced during the development of ISO 9241 caused by the technology being developed faster than we could reach agreement on the standards. I have also explained that ISO 9241-3:1992 now has an Amendment which offers a method of complying with design requirements through user testing which is therefore relatively technology independent. However, standards which specify how products should be made are not the only types of ergonomics standards which are possible. In late 1992, we started work on a process standard ISO 13407-1999 Human-centred design processes for interactive systems which aims to provide guidance for project managers to help them follow a human-centred design process. By undertaking the activities and following the principles described in the standard, managers can be confident that the resulting systems will be usable and work well for their users. The standard describes four principles of human-centred design: § active involvement of users (or those who speak for them) § appropriate allocation of function (making sure human skill is used properly) § iteration of design solutions (allowing time for iteration in project planning) § multi-disciplinary design (but beware over large design teams) § and four key human-centred design activities: § understand and specify the context of use (make it explicit - avoid assuming it is obvious) § specify user and organisational requirements (note there will be a variety of different viewpoints and individual perspectives) § produce design solutions (note plural, multiple designs encourage creativity)
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evaluate designs against requirements (involves real user testing not just convincing demonstrations) In order to claim conformance, the standard requires that the procedures used, the information collected and the use made of results are specified (a checklist is provided as an annex to help). We have developed this approach to conformance in a number of parts of ISO 9241 since so many ergonomics recommendations are context specific. Thus there is often only one ‘shall’ in these standards which generally prescribes what kind of evidence is required to convince another party that the relevant recommendations in the standard have been identified and followed. There has already been considerable international interest in ISO 13407 and we believe there will be increasing demands from large customers for evidence that their system suppliers follow this kind of process. 5.5 The benefits do not just come from the standards themselves There are several ways in which ergonomics standardisation activities can add value to user interface design apart from the standards themselves which are the end results of the process. I have already mentioned that some of those manufacturers who recruited ergonomics and human factors people to defend themselves against standards (my personal and probably somewhat biased view) found that these individuals could add value to the design of user interfaces. Although many of these experts have now joined the ranks of independent consultants, I believe they had a significant impact in terms of raising awareness about the importance of usability. In 1997, the US National Institute of Standards and Technology (NIST) initiated a project (Industry USability Reporting IUSR) to increase the visibility of software usability. They were helped in this endeavour by prominent suppliers of software and representatives from large consumer organisations. One of the key goals was to develop a common usability reporting format (Common Industry Format CIF). This is currently being piloted. Although the effort is independent of other standardisation bodies or activities, the CIF has been developed to be consistent with ISO 9241 and ISO 13407 and is viewed by the IUSR team as ‘an implementation of that ISO work’. I believe this activity in itself will have a major impact on software usability. (http://www.nist.gov/iusr) In the hardware arena, many people are aware of the TCO 99 sticker which appears on computer monitors and understand that it is an indication of ergonomic and environmental quality. What they may not know is that TCO is the Swedish Confederation of White Collar Trades Unions and that ISO 9241 was used as a major inspiration for its original specification. They publish information in English and details are available on their web site at http://www.tco.se/eng/index.htm 5.6 Being international makes it all worthwhile Finally, I am a strong believer in taking a global perspective on ergonomics (and indeed on many other issues. Although there are national and regional differences in populations, the world is becoming a single market with the major suppliers taking a global perspective. Variations in national standards and requirements not only increase costs and complexity, they also tend to compromise individual choice. Making standards international is one way of ensuring that they have impact and can help improve the ergonomics quality of
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products for everyone. That has to be a worthwhile objective. Table 6 shows the member countries of ISO/TC159/SC4. Table 6. ‘P’ Members Members of ISO/TC159/SC4 Ergonomics of Human-System Interaction Austria China Germany Korea Slovakia United Kingdom Australia Tanzania Belgium Denmark Ireland Netherlands Spain United States of America Hungary Canada Finland Italy Norway Sweden Czech Republic France Japan Poland Thailand

‘O’ members

Mexico

Romania

6.

Next steps

Having taken more than seventeen years to develop ISO 9241, you might be forgiven for believing that we would want a rest. In fact, what the experience has taught us is that there is a great deal we would have done differently all these years ago, had we known then what we know now. In ISO/TC 159/SC4, we have recently been trying to apply customer centred methods to our own work. Recognising how long it takes to develop standards and that we do not have unlimited resources, we have been planning our strategy and come to some tentative conclusions for our five year plan. We have identified a number of key standards which we would like to have in place by that time. One major difference from ISO 9241 is that we do not intend to restrict ourselves to office tasks nor indeed do we believe that we should be developing a single family of standards with a common scope or structure. However, we have identified seven areas where we believe we can identify a need for standards and a clear population of potential readers of the standards documents. Although discussions are still at a very early stage, we envisage standards being developed (or existing standards being updated to support: § Visual displays – design and assessment tools for manufacturers, designers, OEMs, testers, evaluators and buyers § Physical input devices - design and assessment tools for manufacturers, testers and selection combination tools for buyers § Voice/speech interface design requirements for application developers § Design process guidance for project managers and designers § Workplace customisation use and selection for system designers in organisations § Interaction, dialogue, navigation and presentation requirements and guidance for application designers § Evaluation, metrics and measurement criteria guidance for end users and managers and test methods for usability experts Although I believe standards are an important tool for the ergonomist, many people find them difficult to understand and use. The best way to really understand what is going on in
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standards is to get involved. This will give you advance warning of future standards, the opportunity to influence the content of standards and an understanding of the context in which they have been developed. You will then find it much easier to make effective use of standards. If you would like more information on ISO, you will find their website an excellent starting point with links to national and other standards sites. (www.iso.ch)

References
Buie, E. 1999, HCI standards: A mixed blessing, Interactions, March/April, volume VI, no. 2 Pages: 36-42. Stewart, T. 1998, Ergonomics standards – the good, the bad and the ugly, Proceedings of the Ergonomics Society Annual Conference. Stewart, T. 1999, Experiences (painful and good) developing HCI standards, Proceedings of Interact 99, (Edinburgh).

Acknowledgements
I would like to thank my many colleagues from around the world with whom I have had the pleasure of working over the past seventeen years in developing standards.

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Table 5. How parts of ISO 9241 were intended to be used in HCI design activities Relevant part of ISO 9241 ISO 9241-11:1998 Guidance on usability Contents Guidance on usability specification which includes descriptions of the context of use, the evaluation procedures to be carried out and the criterion measures to be satisfied when the usability of the system is to be evaluated. There are various situations in which usability may be evaluated, for example in product development, in procurement or in product certification. The common framework presented in this part should be useful in all of these situations. ISO 9241 10:1996 Dialogue High level ergonomic principles which apply to the design of dialogues principles between humans and information systems. These include suitability for the task, controllability and error tolerance amongst others. The principles are supported by a number of scenarios which indicate the relative priorities and importance of the different principles in practical applications. ISO 9241-14 :1997 Menu Recommendations on menu structure, navigation, option selection and dialogues execution, and menu presentation (by various techniques including windowing, panels, buttons, fields, etc.). ISO 9241-15:1998 Command Recommendations on command language structure and syntax, command dialogues representations, input and output considerations, feedback and help. ISO FDIS 9241-16 :1998 Direct Recommendations on the manipulation of objects, and the design of manipulation dialogues metaphors, objects and attributes. It covers those aspects of “Graphical User Interfaces” which are directly manipulated, and not covered by other parts of ISO 9241. ISO 9241-17:1998 Form-filling Recommendations on form structure and output considerations, input dialogues considerations, and form navigation. ISO 9241-3:1992 Display Design of screen hardware for office visual display terminals. In addition to requirements design specifications, this part also contains a proposed user performance test as a test based route to conformance. ISO 9241-7:1998 Requirements for Ergonomic requirements for, and details of, methods of measurement of
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HCI Activity Analysing and defining system requirements

Designing user-system dialogues and interface navigation

Designing or selecting displays

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displays with reflections reflections from the surface of display screens, including those with surface treatments. ISO 9241-8:1997 Requirements for The ergonomic requirements for multi-colour displays which supplement the displayed colours monochrome requirements in Part 3. ISO 9241-12:1998 Presentation of Specific software ergonomics issues involved in representing and presenting information information in visual form. It includes guidance on ways of representing complex information, screen layout and design as well as the use of windows. There is already a substantial body of material available in guidelines and recommendations and this part represents a distillation of the most useful and relevant ones. ISO 9241-4:1998 Keyboard Alphanumeric keyboard specification and design (in terms of the operation of requirements. the keys and its ergonomic qualities) is covered in In addition to design specifications, this part also contains a proposed user performance test as an alternative route to conformance. It deals with the ergonomic aspects of the keyboard, not the layout which is specified in ISO 9995 Keyboard layouts for text office systems. ISO FDIS 9241-9: 1998 Ergonomic requirements for pointing devices including the mouse, tracker ball Requirements for non-keyboard etc. which can be used in conjunction with a visual display terminal. input devices ISO 9241-5:1998 Workstation Ergonomic requirements for a visual display terminal workstation which will layout and postural requirements allow the user to adopt a comfortable and efficient posture. ISO 9241-6:1998 Guidance on the Environmental considerations (visual, acoustic and thermal)) work e environment. ISO 9241-13:1998 User guidance Recommendations for the design and evaluation of user guidance attributes of software user interfaces including Prompts, Feedback, Status, On-line Help and Error Management. ISO 9241-2:1992 Guidance on Guidance on the design of display screen tasks based on nearly half a century task requirements of research and organisational practice in socio-technical systems.

Designing or selecting keyboards and other input devices

Designing workplaces for display screen users

Supporting and training users

Designing jobs and tasks

Interact Consulting, The Ergonomics Training Centre and The Body Garage are divisions of System Concepts Ltd. System Concepts Registered in England no. 205 5814