Conferences

International Scientific Workshop on Ergonomic Aspects of Visual Display Units Milan, 17-19 March 1980

With over 40 papers given by researchers from all over the world this workshop provided a valuable insight into the progress that has been made in the investigation of the human problems of working with visual display units (VDUs).

Prof Etienne Grandjean, the chairman of the workshop, pointed out in his introductory paper that the ergonomics of VDUs is a relatively youthful discipline with much research still needed. He suggested that the solutions to some of the problems are available but that they are not always applied. Many of the subsequent papers provided ample evidence of the problems associated with using a VDU. Speaker after speaker presented the results of surveys quantifying the complaints and discomfort of VDU operators and linking these with the design of the visual display, the workstation and the visual task of the user.

The first half of this workshop was dominated by papers concerned with the effect of VDUs on the visual function, though it emerged that we are no nearer an easy-to-use index of visual fatigue. Considering the number of papers on the optical qualities of VDUs and associated opthalmic studies, there was very little by way of new conclusions.

However, two papers from West Germany indicated the superiority of displays utilising dark characters on a light background compared with the more common light characters on a dark background. But both speakers had performed their experiments on new displays that incorporated other technological changes in addition to the reversal of the screen contrast.

There were very few papers concerned with the use of multi-colour visual displays and those that did illustrated the urgent need for more research in this area. Prof Halder, whose previous work on the after effects of particular screen colours has been very influential, suggested that yellow as well as green could be used more widely in the future.

A number of papers illustrated the benefit of adjustable workstations

movable keyboards and document holders for the VDU operator. In general, these papers reinforced existing knowledge, though Prof Grandjean was particularly critical of the small backrests provided on most VDU operators' chairs. He suggested that the backrest should be adjustable and at least 50 cm high.

Several papers emphasised the importance of good job design for the VDU operator. Prof Margulies from Austria insisted that the work content must be considered, and called for ergonomists to take more note of job content and the aspirations of VDU operators. Dr K. Buhmann from West Germany emphasised the need for 'whole jobs' with flexible time structure and suggested that inflexible rest regulations would not solve operator problems.

Although there has been a considerable amount of work in the USA on the ergonomics of VDUs, a paper presented by Prof Smith was unusual in that it reported a survey of VDU operator stress in the USA. Prof Smith concluded that job demands are a strong determinant of health complaints and contribute significantly to stress in VDU operators.

It was refreshing to see that many of the studies, reported during the workshop, included data collected from control groups of clerks and typists no tus ing VDUs. Different studies concerned with constrained posture, visual fatigue and job stress all utilising control groups illustrated significant differences in the incidences of complaints and discomfort experienced by VDU operators and non-VDU operators.

Considering that the meeting was intended to be a scientific workshop there was very little opportunity for detailed discussion. This was not helped by the absence of any organised refreshment facilities between the workshop sessions. Despite the withdrawal of ten papers from the originally published programme the presentations were compressed into an exhausting 2% days in a grand but inadequate room with very uncomfortable seating.

One area of discussion that was of note followed the presentation of Dr Buhmann from West Germany in which he stated the need for regulations concerning the design and use of VDUs. Prof Grandjean suggested that too

little was known about certain aspects of VDU usage and to produce binding regulations would be premature. In response, Dr Buhmann stated that a large number of legally binding agreements were already in existence in West Germany and that many disagreed with one another. Thus there was an urgent need for some standardised regulations. Tom Stewart suggested that any standards or regulations relating to VDUs should state the desired objectives rather than quote specific levels or items that could well inhibit the use of some new improved display technology.

During the workshop it became apparent that delegates were using various technical terms in different ways. This was particularly confusing during the discussion on displays that had dark characters on a light back- ground. Some delegates referred to this as positive contrast while others described it as negative contrast. Differences in interpretation were also apparent in the use of the terms brightness, flicker and modulation. While some of these confusions may have been caused by translation difficulties there is obviously an urgent need for discussion and standardisation of these terms amongst the international ergonomics community.

A paper from the ITT Human Factors group in the UK reported a commendable attempt to communicate the available ergonomics information concerning VDUs. Three documents are being prepared with quite different audiences in mind: the VDU designer, the VDU operator and the VDU purchaser.

While many European manufacturers of computers and VDUs produce glossy ergonomics brochures as part of their marketing strategy, their objectivity is sometimes coloured by their vested interest. It remains to be seen whether the objective human factors advice that was originally included in the three proposed documents will survive the marketing men's censorship.

Perhaps the most surprising omission during the workshop was any significant contribution concerning the ergonomics of the software. Passing reference was made to dialogue design by a number of speakers but there are a host of complex issues in this area that are in urgent need of detailed research.

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Though there was little by way of completely new findings presented, the workshop was valuable in that the papers provided empirical support for many of the reported problems and existing ergonomic recommendations concerning the design and use of VDUs. However, one unscheduled paper did surprise many of the delegates. Dr H. Tjonn from the Norwegian Directorate of Labour Inspection revealed ten possible cases of facial dermatitis among VDU operators in different parts of Norway. Dr Tjonn appealed

to doctors in other countries for reports of any similar problems associated with the use of VDUs.

One final reflection on the workshop concerns the different types of contribution from different countries. It was most noticeable that speakers from countries such as West Germany and Sweden that have programmes and legislation that support research into the humanisation of work made the most significant scientific contribution to the workshop. Many of the other papers were obviously based upon very

thorough experiments and surveys that allowed the problems to be quantified.

This was in sharp contrast to the speakers from the UK who seemed to follow a more pragmatic approach that attempted to solve the problems. Without wishing to criticise either approach one was left with the feeling of a distinct gulf between some of the 'clinical' resealchers and the practicising ergonomists.

Brian Pearce

182 Applied Ergonomics September 1980