Improving VDT workplaces in offices by use of a physiologically optimized screen with black symbols on a light background: basic considerations

. A physiologically optimized bright screen with dark characters has been developed in an effort to eliminate the visual problems and design restrictions which are commonly found in conventional VDTs, as described in numerous publications. It is designed to give a near optimum of visual acuity. Its character sharpness is significantly better than equivalent bright characters on dark backgrounds. By choosing an appropriate black character matrix, screen characters may be made to highly resemble carbon typed characters on a white piece of paper.

Inherent problems of the 50-60 Hz dark-background screen—blackness of the background, inappropriate adaptation level, gross level differences between screen and document, sensitivity to specular and diffuse reflections—have been eliminated by a light-background VDT, which is flicker- and jitter-free and which uses correctly designed optics.

The experimental unit tolerates source luminances up to 2000 cd/m² and vertical illumination levels up to around 6000 lx without essential degradation of readability. Consequently, a considerable degree of freedom in designing a VDT workroom is gained: optimum office illumination without restrictions imposed by inappropriate VDUs is possible even in situations where, in one workroom, work which needs high-level illumination and VDT work exist side by side.     

Postures and the design of VDT workstations

With the introduction of VDTs many office employees became part of a man-machine system with close physical binding to the workstation. Constrained postures associated with muscle fatigue and sometimes with impairments involving joints or tendons can occur.

Field studies revealed a certain incidence of physical discomfort in the neck-shoulder-arm-hand area. These troubles may also occur in other strenuous office jobs. An increased incidence of physical discomfort'and medical findings is observed when keyboard levels are too low, when forearm and wrists cannot rest on an adequate support and when the design of the keyboard itself is too high.

A study of preferred settings and postures at adjustable VDT workstations under practical conditions revealed the need for relatively wide ranges of adjustable dimensions. The operators prefer postures similar to those of car drivers: they lean backwards with upper arms kept higher than expected and slightly opened elbow angles. Recommendations are drawn from these studies for the proper design of VDT workstations concerning the ranges of adjustability, the leg room and the chair.     

Visual discrimination on colour VDTs at two viewing distances

The paper describes a research study on visual discrimination of textual and graphic symbols on a visual display terminal (VDT) screen when viewed at eye-lo-screen distances of 61 cm and 152 cm (24 and 60 ins). Conducted as part of a development programme at McDonnell Douglas Corporation's St. Louis Aircraft Company for an Integrated Manufacturing Composites Centre (ICC), the study investigated symbol shapes, symbol sizes, symbol colours and background colours at the two viewing distances. The longer distance is representative of required placements of the VDTs at some manufacturing workstations to avoid interference with process or control equipment. Knowledge gained from the study was incorporated in the selection of the manufacturing computer information system (CIS) terminals.

All four treatments showed significant effects on visual discrimination at both viewing distances and, particularly at the 152 cm distance, the mix of symbol and background colours was highly significant. A black screen background colour with more luminous symbols such as orange, green, yellow provided much better visual discrimination at the extended viewing distance than less luminous symbols such as red and blue on a white background. Visual discrimination at the extended viewing distance, when compared with the shorter viewing distance and using symbols of equal size, was better than the loss in visual angle would suggest.

Sex and age (to age 65) did not significantly affect visual discrimination mean scores, but the variance among individuals in the 51-65 years age group was greater than for the younger age groups.

The visual discrimination scores for symbol sizes of 4 mm² were not significantly different from the 6 mm² symbols at the 61 cm viewing distance. The 4 mm² symbol size was therefore adequate for visual discrimination of standalone symbols at this distance. Although 8 mm symbols were not used in this study, projections from the data indicate that such symbol sizes at 152 cm would provide comparable discrimination scores to the 4 mm² at 61 cm.

Improved visual discrimination of standalone symbols occurs with gaps or changes in the angles of symbols, such as sets 'C' versus 'O' and 'Xl' versus'+'.     

Occupational stress factors in visual display terminal (VDT) operation: a review of empirical research

A review of the literature involving empirical research (experimental and field investigations) on stressful aspects of visual display terminal (VDT) operation is presented. Studies reviewed included assessment of visual fatigue and/or performance, musculoskeletal symptoms and operator attitudes towards job demands and quality of working life. In addition, some investigation included discussions and evaluations of the physical attributes of VDT workplaces; including ergonomic factors (task lighting, glare conditions, anthropometric configuration of VDT and accompanying furniture), environmental factors (temperature, humidity, radiation) and psychosocial factors (job demand, work content, work-rest schedules).

The literature reveals that levels of visual and musculoskeletal complaints among VDT operators are high. Moreover, ergonomic field assessment of VDT workplaces indicate that the majority of those examined were suboptimal with respect to existing recommendations regarding lighting, glare control and anthropometric dimensions of screen, keyboard, desk and chair. Nevertheless, evidence of causal linkages between specific ergonomic attributes of the workplace and specific patterns of symptomatology are lacking.

Finally, work demand and task structure attributes to the VDT operation were demonstrated to have strong effects on incidences of reports of visual and postural symptoms as well as on psychosocial attitudinal indicators. Hence, it is argued that approaches toward stress reduction must include job content as well as ergonomic factors.     

Taskmaster: an interactive, graphical environment for task specification, execution and monitoring

Taskmaster is an interactive environment that employs a unique blend of graphic technologies and iconic images to support user task specification. In this environment, problem solving is based on the selection, specification, and composition of tools that correspond to natural sets of ordered operations. The Taskmaster environment is novel in that it

(provides an interactive, visual-based approach to user task specification;

(encourages and supports task specification and refinement processes from both the top-down and bottom-up perspectives; and

(enables one to specify parallel tasks in a natural and convenient manner

To “program” a given task within the Taskmaster environment, one decomposes it into an ordered set of conceptually simple, high-level operations, and then combines (composes) a corresponding network of software tools that implements these operations. Execution of the specified network provides a task solution. Major system components supporting user task specification include a network editor, a tools database and a network execution monitor.     

A longitudinal study of VDT work and health

A longitudinal study on the use of visual display terminals (VDTs) was conducted with questionaire data obtained 1981 and in 1987–1988 from a cohort of office workers. The use of VDTs became more widespread in these offices during the intervening time period, but the time spent by individuals working at VDTs showed no general increase. The data suggested that VDT use was related to the risk of developing eye discomforts and hand and wrist problems. For skin problems and headache, risks for VDT and non‐VDT users were fairly similar, but indications of increased risks were found for certain groups and situations. The risks of developing neck, shoulder, shoulder joint, or upper arm problems were high for both VDT and non‐VDT users, but there were, in this study, no convincing suggestions that these risks were higher for VDT users compared to nonusers.     

Mental and physical strain at VDT workstations

. There are millions of workers worldwide who use video display terminals (VDTs) on a daily basis. Over the past decade VDT users have reported a variety of health complaints that have been associated with VDTs including visual and musculoskeletal discomfort and psychological distress. In addition VDT users have expressed fears about radiation from VDTs and more recently concerns about adverse reproductive effects. This paper explores the potential health effects of working at a VDT based on an evaluation of current research literature and indicates where more research is underway or needed to better define health risks. Some conclusions about the seriousness of potential health effects are presented.     

Video display terminals and vision of workers Summary and overview of a symposium

This summary discusses issues raised at a National Research Council symposium on vision and VDT work, held at the request of the National Institute for Occupational Safety and Health. Symposium participants critically reviewed laboratory studies of visual function and field surveys of visual complaints of VDT operators to determine what conclusions can be drawn about the prevalence, severity, causes of, and possible remedies for reported difficulties. Although speakers' perspectives differed, a number of points appeared to gain consensus: (i) properly designed epidemiologies) studies comparing the incidence of visual problems in VDT operators with that in non-VDT workers are needed, (ii) Visual issues are closely interrelated with ergonomic and job design variables, and use of multivariate statistical analysis is necessary to determine what specific aspects of work involving VDTs may contribute to visual and other complaints, (iii) No scientifically valid study has established that VDT use causes harm, in the sense of damage, to the visual system, (iv) Existing knowledge indicates a number of measures that could be taken to improve worker comfort and performance: use of high-quality displays; control of workplace lighting conditions; application of principles of anthropometric design; and consideration of workers' needs in design of jobs, (v) Surveys of radiation emissions from VDTs indicate that levels of radiation are far below U.S. occupational exposure standards. Published data provide no evidence that cateracts are associated with VDT use. (vi) Standards should be based on research. Differing opinions on whether setting standards is useful and appropriate point to the need for caution in this area. Needs for further research were identified.     

Commerce by Any Other Name

D.F. Aldrich, Mastering the Digital Marketplace: Practical Strategies for Competitiveness in the New Economy, New York, NY: Wiley (2000) 309 pp.

R. Kalakota and M. Robinson, e-Business: Roadmap for Success, Reading, MA: Addison-Wesley (1999) 378 pp.

R. Murch and T. Johnson, Intelligent Software Agents, Upper Saddle River, NJ: Prentice Hall PTR, (1999) 210 pp.

R. T. Watson, P. Berthon, L.F. Pitt, and G.M. Zinkhan, Electronic Commerce: the Strategic Perspective, Ft. Worth, TX: the Dryden Press (2000) 162 pp.

J. Christopher Westland and T.K.H. Clark, Global Electronic Commerce: Theory and Cases, Cambridge, MA: MIT Press (2000) 585 pp.     

It is 11 O'Clock. Do You Know What Your Competitor is Doing?

From Knowledge to Intelligence: Creating Competitive Advantage in the New Economy by Helen N. Rothberg and

G. Scott Erickson, Amsterdam: Elsevier Butterworth Heinemann (2005), 365 pp.

Competitive Intelligence and Global Business edited by David L. Blenkhorn and Craig S. Fleischer, Westport, CT: Praeger Publishers (2005), 292 pp.

Outsource: Competing in the Global Productivity Race by Edward Yourdon, Boston: Prentice Hall PTR (2005), 251 pp.

Digital Infrastructures: Enabling Civil and Environmental Systems through Information Technology edited by Rae Zimmerman and Thomas Horan, London: Routledge (2005), 254 pp.

Decision Support Systems: Frequently Asked Questions by Daniel J. Power, New York: iUniverse Inc. (2005), 232 pp.     

E-Commerce Overviews and Close-Ups

Soon-Yong Choi, Dale O. Stahl, and Andrew B. Whinston, The Economics of Electronic Commerce: the Essential Economics of Doing Business in the Electronic Marketplace. Indianapolis: Macmillan Technical Publishing, 1997, 626 pp.

Mellanie Hills, Intranet Business Strategies. New York: John Wiley & Sons, 1997, 396 pp.

David Hudson, Rewired. Indianapolis, IN: Macmillan Technical Publishing, 1997, 327 pp.

Ravi Kalakota and Andrew B. Whinston, Electronic Commerce, A Manager's Guide. Reading, MA: Addison-Wesley, 1998, 431 pp.

Ravi Kalakota and Andrew B. Whinston (eds.), Readings in Electronic Commerce, Reading, MA: Addison-Wesley, 1997, 340 pp.

Ravi Kalakota and Andrew B. Whinston, Frontiers of Electronic Commerce, Reading, MA: Addison-Wesley, 1996, 850 pp.

Lee W. McNight and Joseph P. Bailey (eds.), Internet Economics. Cambridge, MA: the MIT Press, 525 pp.     

Fighting Malware and Other Unspeakable Threats

John Gantz and Jack M. Rochester. Pirates of the Digital Millennium: How the Intellectual Property Wars Damage

Our Personal Freedoms, Our Jobs, and the World Economy, Upper Saddle River, NJ: Prentice Hall Financial Times (2005), 294 pp.

Thomas R. Peltier, Justin Peltier, and John Blackley. Information Security Fundamentals, Boca Raton, FL: Auerbach Publications (2005), 262 pp.

Paul Reid. Biometrics for Network Security, Upper Saddle River, NJ: Prentice Hall PTR (2004), 252 pp.

Robert M. Slade. Software Forensics, New York: McGraw-Hill (2004), 215 pp.     

The Leading Edge in is Management

Jean Lipman-Blumen and Harold J. Leavitt, Hot Groups: Seeding Them, Feeding Them, and Using Them to Ignite Your Organization, New York: Oxford University Press (1999) 296 pp.

Thomas H. Davenport, Mission Critical: Realizing the Promise of Enterprise Systems, Boston: Harvard Business School Press (2000) 336 pp.

W.H. Inmon, Ken. Rudin, Christopher K. Buss, and Ryan Sousa, Data Warehouse Performance, New York: Wiley (1999) 444 pp.

Jay Liebowitz (ed.) Knowledge Management Handbook, CRC Press (1999) 312 pp.     

New Thinking About the Enterprise

Geographic Information Systems in Business, James B. Pick, Editor; Hershey, PA: Idea Group Publishing (2005).

Sharing Expertise: Beyond Knowledge Management, Mark Ackerman, Volkmar Pipek, and Volker Wulf, Editors; Cambridge, MA: MIT Press (2003).

Innovations in Knowledge Management, Bonnie Montano, Editor; Hershey, PA: IRM Press (2005).

Business Intelligence for the Enterprise, by Mike Biere; Upper Saddle River, NJ: Prentice Hall, (2003).     

Economic Visions

Jason Dedrick and Kenneth L. Kraemer, Asia's Computer Challenge: Threat or Opportunity for the United States and the World? New York: Oxford University Press (1998) 364 pp. ISBN 0-19-512201-1

Bill Gates with Collins Hemingway, Business the Speed of Thought, New York: Warner Books (1999) 470 pp. ISBN 0-446-52568-5

Henry C. Lucas, Jr., Information Technology and the Productivity Paradox: Assessing the Value of Investing in IT, New York: Oxford University Press (1999) 225 pp. ISBN 0-19-512159-7

Carl Shapiro and Hal R. Varian, Information Rules: A Strategic Guide to the Network Economy, Boston, MA: Harvard Business School Press (1999) 384 pp. ISBN 0-87584-863-X     

Postural and visual loads at VDT workplaces II. Lighting conditions and visual impairments

Four groups of office tasks were studied: data entry terminals, conversational terminals, traditional office work and typing. Eye impairments were observed in every group of office employees but the impairments were more frequent in VDT operators. The impairments persisted during leisure time. Vision screening tests showed the same incidence of functional eye impairments in office tasks with and without VDTs. High luminance contrasts between screen, source document and the surrounding space were associated with an increase in eye troubles. Increased oscillating luminance of screen characters was associated with lower visual acuity, and with a higher incidence of subjective and objective symptoms of eye irritation including more frequent use of eye drops. The degree of luminance oscillation of characters must be considered as an important factor in eye strain at VDT workplaces. Employees with eye defects (glasses, lowered visual acuity, uncorrected eye defects) had in general a somewhat higher incidence of eye complaints     

The New Business Currency

Thomas H. Davenport and John C. Beck, The Attention Economy: Understanding the New Currency of Business, Boston, MA: Harvard Business School Press (2001), 253 pp.

Brad Hansen, The Dictionary of Computing and Digital Media: Terms and Acronyms, Wilsonville, OR: Franklin, Beedle, and Associates (1999), 543 pp.

Piotr Jankowski and Timothy Nyerges, Geographic Information Systems for Group Decision Making: Towards a Participatory Geographic Information Science, New York: Taylor and Francis (2001), 273 pp.

Jeffrey A. Rohlfs, Bandwagon Effects in High Technology Industries, Cambridge, MA: MIT Press (2001), 256 pp.     

Bundles from Britain

Ciborra, Claudio U., ed., Groupware and Teamwork: Invisible Aid or Technical Hindrance? (Chichester, U.K.: John Wiley & Sons, 1996), 240 pp.

Galliers, Robert D. and Walter J. Bates, eds., Information Technology and Organizational Transformation: Innovation for the 21st Century (Chichester, U.K.: John Wiley & Sons, 1996), 240 pp.

Klepper, Robert and Wendell O. Jones, Outsourcing Information Technology, Systems, and Services (Upper Saddle River, NJ: Prentice-Hall PTR, 1998), 392 pp.

Remenyi, Dan, Michael Sherwood-Smith, with Terry White, Achieving Maximum Value from Information Systems: A Process Approach (Chichester, U.K.: John Wiley & Sons, 1997). 262 pp.

Wigand, Rolf, Arnold Picot, and Ralf Reichwald, Information, Organization, and Management: Expanding Markets and Corporate Boundaries (Chichester, U.K.: John Wiley & Sons, 1997), 458 pp.

Willcocks, Leslie P. and Mary C. Lacity, eds., Strategic Sourcing of Information Systems: Perspectives and Practices (Chichester, U.K.: John Wiley & Sons, 1997), 262 pp.     

Emotional Intelligence

Daniel Goleman, Richard Boyatzis, and Annie McKee, Primal Leadership: Realizing the Power of Emotional Intelligence, Boston: Harvard Business School Press (2002), 306 pp.

Dennis N.T. Perkins, with Margaret P. Holtman, Paul R. Kessler, and Catherine McCarthy, Leading at the Edge: Leadership Lessons from the Extraordinary Saga of Shackleton's Antarctic Expedition, New York: AMACOM (2000), 268 pp.

Charles C. Manz, Emotional Discipline: the Power to Choose How You Feel, San Francisco: Barrett-Koehler Publishers, Inc. (2003), 234 pp.

Cliff Hakim, We Are All Self-Employed: How to Take Control of Your Career, San Francisco: Barrett-Koehler Publishers, Inc. (2003), 261 pp.     

A laboratory study on preferred and imposed settings of a VDT workstation

Thirty trained female typists performed several consecutive l0min typing tasks on an adjustable VDT workstation. The experiments were conducted with preferred as well as with imposed settings. The body postures were determined during the typing tasks and the subjects filled out questionnaires at the end of the tasks.

The study discloses that the preferred workstation dimensions are associated with mainly 'relaxed' sensations, while imposed dimensions—even if they are similar to the mean values of preferred settings—cause an increased incidence of static load symptoms in the sense of increased tension or impairments in the neck-shoulder-arm-hand area. The preferred keyboard levels are mainly distinctly higher than those recommended in standards and brochures. A chair with a high backrest and a proper support to rest forearms and wrists are preconditions for the preferred postures at VDT workstations.