Friday, 25 March 2011 03:40

Overview

Rate this item
(1 Vote)

New information technologies are being introduced in all industrial sectors, albeit to varying extents. In some cases, the costs of computerizing production processes may constitute an impediment to innovation, particularly in small and medium-sized companies and in developing countries. Computers make possible the rapid collection, storage, processing and dissemination of large quantities of information. Their utility is further enhanced by their integration into computer networks, which allow resources to be shared (Young 1993).

Computerization exerts significant effects on the nature of employment and on working conditions. Beginning about the mid-1980s, it was recognized that workplace computerization may lead to changes in task structure and work organization, and by extension to work requirements, career planning and stress suffered by production and management personnel. Computerization may exert positive or negative effects on occupational health and safety. In some cases, the introduction of computers has rendered work more interesting and resulted in improvements in the work environment and reductions of workload. In others, however, the result of technological innovation has been an increase in the repetitive nature and intensity of tasks, a reduction of the margin for individual initiative and the isolation of the worker. Furthermore, several companies have been reported to increase the number of work shifts in an attempt to extract the largest possible economic benefit from their financial investment (ILO 1984).

As far as we have been able to determine, as of 1994 statistics on the worldwide use of computers are available from one source only—The Computer Industry Almanac (Juliussen and Petska-Juliussen 1994). In addition to statistics on the current international distribution of computer use, this publication also reports the results of retrospective and prospective analyses. The figures reported in the latest edition indicate that the number of computers is increasing exponentially, with the increase becoming particularly marked at the beginning of the 1980s, the point at which personal computers began to attain great popularity. Since 1987, total computer processing power, measured in terms of the number of million instructions per second executed (MIPS) has increased 14-fold, thanks to the development of new microprocessors (transistor components of microcomputers which perform arithmetical and logical calculations). By the end of 1993, total computing power attained 357 million MIPS.

Unfortunately, available statistics do not differentiate between computers used for work and personal purposes, and statistics are unavailable for some industrial sectors. These knowledge gaps are most likely due to methodological problems related to the collection of valid and reliable data. However, reports of the International Labour Organization’s tripartite sectoral committees contain relevant and comprehensive information on the nature and extent of the penetration of new technologies in various industrial sectors.

In 1986, 66 million computers were in use throughout the world. Three years later, there were more than 100 million, and by 1997, it is estimated that 275–300 million computers will be in use, with this number reaching 400 million by 2000. These predictions assume the widespread adoption of multimedia, information highway, voice recognition and virtual reality technologies. The Almanac’s authors consider that most televisions will be equipped with personal computers within ten years of publication, in order to simplify access to the information highway.

According to the Almanac, in 1993 the overall computer: population ratio in 43 countries in 5 continents was 3.1 per 100. It should however be noted that South Africa was the only African country reporting and that Mexico was the only Central American country reporting. As the statistics indicate, there is a very wide international variation in the extent of computerization, the computer:population ratio ranging from 0.07 per 100 to 28.7 per 100.

The computer:population ratio of less than 1 per 100 in developing countries reflects the generally low level of computerization prevailing there (table 1) (Juliussen and Petska-Juliussen 1994). Not only do these countries produce few computers and little software, but lack of financial resources may in some cases prevent them from importing these products. Moreover, their often rudimentary telephone and electrical utilities are often barriers to more widespread computer use. Finally, little linguistically and culturally appropriate software is available, and training in computer-related fields is often problematic (Young 1993).

 


Table 1. Distribution of computers in various regions of the world

 

REGION

COMPUTERS PER 100 PEOPLE

   

NORTH AMERICA

 

   United States

28.7

   Canada

8.8

CENTRAL AMERICA

 

   Mexico

1.7

SOUTH AMERICA

 

   Argentina

1.3

   Brazil

0.6

   Chile

2.6

   Venezuela

1.9

WESTERN EUROPE

 

   Austria

9.5

   Belgium

11.7

   Denmark

16.8

   Finland

16.7

   France

12.9

   Germany

12.8

   Greece

2.3

   Ireland

13.8

   Italy

7.4

   Netherlands

13.6

   Norway

17.3

   Portugal

4.4

   Spain

7.9

   Sweden

15

   Switzerland

14

   United Kingdom

16.2

EASTERN EUROPE

 

   Czech Republic

2.2

   Hungary

2.7

   Poland

1.7

   Russian Federation

0.78

   Ukraine

0.2

OCEANIA

 

   Australia

19.2

   New Zealand

14.7

AFRICA

 

   South Africa

1

ASIA

 

   China

0.09

   India

0.07

   Indonesia

0.17

   Israel

8.3

   Japan

9.7

   Korea, Republic of

3.7

   Phillipines

0.4

   Saudi Arabia

2.4

   Singapore

12.5

   Taiwan

7.4

   Thailand

0.9

   Turkey

0.8

Less than 1

1 - 5   6 - 10   11 - 15   16-20   21 - 30

Source: Juliussen and Petska-Juliussen 1994.


 

Computerization has significantly increased in the countries of the former Soviet Union since the end of the Cold War. The Russian Federation, for example, is estimated to have increased its stock of computers from 0.3 million in 1989 to 1.2 million in 1993.

The largest concentration of computers is found in the industrialized countries, especially in North America, Australia, Scandinavia and Great Britain (Juliussen and Petska-Juliussen 1994). It was principally in these countries that the first reports of visual display unit (VDU) operators’ fears regarding health risks appeared and the initial research aimed at determining the prevalence of health effects and identifying risk factors undertaken. The health problems studied fall into the following categories: visual and ocular problems, musculoskeletal problems, skin problems, reproductive problems, and stress.

It soon became evident that the health effects observed among VDU operators were dependent not only on screen characteristics and workstation layout, but also on the nature and structure of tasks, organization of work and manner in which the technology was introduced (ILO 1989). Several studies have reported a higher prevalence of symptoms among female VDU operators than among male operators. According to recent studies, this difference is more reflective of the fact that female operators typically have less control over their work than do their male counterparts than of true biological differences. This lack of control is thought to result in higher stress levels, which in turn result in increased symptom prevalence in female VDU operators.

VDUs were first introduced on a widespread basis in the tertiary sector, where they were used essentially for office work, more specifically data entry and word processing. We should not therefore be surprised that most studies of VDUs have focused on office workers. In industrialized countries, however, computerization has spread to the primary and secondary sectors. In addition, although VDUs were used almost exclusively by production workers, they have now penetrated to all organizational levels. In recent years, researchers have therefore begun to study a wider range of VDU users, in an attempt to overcome the lack of adequate scientific information on these situations.

Most computerized workstations are equipped with a VDU and a keyboard or mouse with which to transmit information and instructions to the computer. Software mediates information exchange between the operator and the computer and defines the format with which information is displayed on the screen. In order to establish the potential hazards associated with VDU use, it is first necessary to understand not only the characteristics of the VDU but also those of the other components of the work environment. In 1979, Çakir, Hart and Stewart published the first comprehensive analysis in this field.

It is useful to visualize the hardware used by VDU operators as nested components that interact with each other (IRSST 1984). These components include the terminal itself, the workstation (including work tools and furniture), the room in which the work is carried out, and the lighting. The second article in this chapter reviews the main characteristics of workstations and their lighting. Several recommendations aimed at optimizing working conditions while taking into account individual variations and variations in tasks and work organization are offered. Appropriate emphasis is placed on the importance of choosing equipment and furniture which allow flexible layouts. This flexibility is extremely important in light of international competition and rapidly evolving technological development that are constantly driving companies to introduce innovations and while simultaneously forcing them to adapt to the changes these innovations bring.

The next six articles discuss health problems studied in response to fears expressed by VDU operators. The relevant scientific literature is reviewed and the value and limitations of research results highlighted. Research in this field draws upon numerous disciplines, including epidemiology, ergonomics, medicine, engineering, psychology, physics and sociology. Given the complexity of the problems and more specifically their multifactorial nature, the necessary research has often been conducted by multidisciplinary research teams. Since the 1980s, these research efforts have been complemented by regularly organized international congresses such as Human-Computer Interaction and Work with Display Units, which provide an opportunity to disseminate research results and promote the exchange of information between researchers, VDU designers, VDU producers and VDU users.

The eighth article discusses human-computer interaction specifically. The principles and methods underlying the development and evaluation of interface tools are presented. This article will prove useful not only to production personnel but also those interested in the criteria used to select interface tools.

Finally, the ninth article reviews international ergonomic standards as of 1995, related to the design and layout of computerized workstations. These standards have been produced in order to eliminate the hazards to which VDU operators can be exposed in the course of their work. The standards provide guidelines to companies producing VDU components, employers responsible for the purchase and layout of workstations, and employees with decision-making responsibilities. They may also prove useful as tools with which to evaluate existing workstations and identify modifications required in order to optimize operators’ working conditions.

 

Back

Read 4622 times Last modified on Saturday, 30 July 2022 23:34

" DISCLAIMER: The ILO does not take responsibility for content presented on this web portal that is presented in any language other than English, which is the language used for the initial production and peer-review of original content. Certain statistics have not been updated since the production of the 4th edition of the Encyclopaedia (1998)."

Contents

Visual Display Units References

Akabri, M and S Konz. 1991. Viewing distance for VDT work. In Designing For Everyone, edited by Y Queinnec and F Daniellou. London: Taylor & Francis.

Apple Computer Co. 1987. Apple Human Interface Guidelines. The Apple Desktop Interface. Waltham, Mass.: Addison-Wesley.

Amick, BC and MJ Smith. 1992. Stress, computer-based work monitoring and measuring systems: A conceptual overview. Appl Ergon 23(1):6-16.

Bammer, G. 1987. How technologic change can increase the risk of repetitive motions injuries. Seminars Occup Med 2:25-30.

—. 1990. Review of current knowledge -Musculoskeletal problems. In Work With Display Units 89: Selected Papers from the Work with Display Units Conference, September 1989, Montreal, edited by L Berlinguet and D Berthelette. Amsterdam: North Holland.

Bammer, G and B Martin. 1988. The arguments about RSI: An examination. Community Health Stud 12:348-358.

—. 1992. Repetition strain injury in Australia: Medical knowledge, social movement and de facto partisanship. Social Prob 39:301-319.

Bastien, JMC and DL Scapin. 1993. Ergonomic criteria for the evaluation of human-computer interfaces. Technical Report no. 156, Programme 3 Artificial Intelligence, cognitive systems, and man-machine interaction. France: INRIA.

Berg, M. 1988. Skin problems in workers using visual display terminals: A study of 201 patients. Contact Dermat 19:335-341.

—-. 1989. Facial skin complaints and work at visual display units. Epidemiological, clinical and histopathological studies. Acta Derm-Venereol Suppl. 150:1-40.

Berg, M, MA Hedblad, and K Erkhardt. 1990. Facial skin complaints and work at visual display units: A histopathological study. Acta Derm-Venereol 70:216-220.

Berg, M, S Lidén, and O Axelson. 1990. Skin complaints and work at visual display units: An epidemiological study of office employees. J Am Acad Dermatol 22:621-625.

Berg, M, BB Arnetz, S Lidén, P Eneroth, and A Kallner. 1992. Techno-stress, a psychophysiological study of employees with VDU-associated skin complaints. J Occup Med 34:698-701.

Bergqvist, U. 1986. Pregnancy and VDT work -An evaluation of the state of the art. In Work With Display Units 86: Selected Papers from the International Scientific Conference On Work With Display Units, May 1986, Stockholm, edited by B Knave and PG Widebäck. Amsterdam: North Holland.

Bikson, TK. 1987. Understanding the implementation of office technology. In Technology and the Transformation of White-Collar Work, edited by RE Kraut. Hillsdale, NJ: Erlbaum Associates.

Bjerkedal, T and J Egenaes. 1986. Video display terminals and birth defects. A study of pregnancy outcomes of employees of the Postal-Giro-Center, Oslo, Norway. In Work With Display Units 86: Selected Papers from the Interantional Scientific Conference On Work With Display Units, May 1986, Stockholm, edited by B Knave and PG Widebäck. Amsterdam: North Holland.

Blackwell, R and A Chang. 1988. Video display terminals and pregnancy. A review. Brit J Obstet Gynaec 95:446-453.

Blignault, I. 1985. Psychosocial aspects of occupational overuse disorders. Master of Clinical Psychology Thesis, Department of Psychology, The Australian National University, Canberra ACT.

Boissin, JP, J Mur, JL Richard, and J Tanguy. 1991. Study of fatigue factors when working on a VDU. In Designing for Everyone, edited by Y Queinnec and F Daniellou. London: Taylor & Francis.

Bradley, G. 1983. Effects of computerization on work environment and health: From a perspective of equality between sexes. Occup Health Nursing :35-39.

—. 1989. Computers and the Psychological Environment. London: Taylor & Francis.
Bramwell, RS and MJ Davidson. 1994. Visual display units and pregnancy outcome: A prospective study. J Psychosom Obstet Gynecol 14(3):197-210.

Brandt, LPA and CV Nielsen. 1990. Congenital malformations among children of women working with video display terminals. Scand J Work Environ Health 16:329-333.

—. 1992. Fecundity and the use of video display terminals. Scand J Work Environ Health 18:298-301.

Breslow, L and P Buell. 1960. Mortality and coronary heart disease and physical activity on work in California. J Chron Dis 11:615-626.

Broadbeck, FC, D Zapf, J Prumper, and M Frese. 1993. Error handling in office work with computers: A field study. J Occup Organ Psychol 66:303-317.

Brown, CML. 1988. Human-Computer Interface Guidelines. Norwood, NJ: Ablex.

Bryant, HE and EJ Love. 1989. Video display terminal use and spontaneous abortion risk. Int J Epidemiol 18:132-138.

Çakir, A. 1981. Belastung und Beanspruching bei Biuldschirmtätigkeiten. In Schriften zur Arbeitspychologie, edited by M Frese. Bern: Huber.

Çakir, A, D Hart, and TFM Stewart. 1979. The VDT Manual. Darmstadt: Inca-Fiej Research Association.

Carayon, P. 1993a. Job design and job stress in office workers. Ergonomics 36:463-477.

—. 1993b. Effect of electronic performance monitoring on job design and worker stress: A review of the literature and conceptual model. Hum Factors 35(3):385-396.

Carayon-Sainfort, P. 1992. The use of computers in offices: Impact on task characteristics and worker stress. Int J Hum Comput Interact 4:245-261.

Carmichael, AJ and DL Roberts. 1992. Visual display units and facial rashes. Contact Dermat 26:63-64.

Carroll, JM and MB Rosson. 1988. Paradox of the active user. In Interfacing Thought. Cognitive Aspects of Human-Computer Interaction, edited by JM Carroll. Cambridge: Bradford.

Cohen, ML, JF Arroyo, GD Champion, and CD Browne. 1992. In search of the pathogenesis of refractory cervicobrachial pain syndrome. A deconstruction of the RSI phenomenon. Med J Austral 156:432-436.

Cohen, S and N Weinstein. 1981. Nonauditory effects of noise on behavior and health. J Soc Issues 37:36-70.

Cooper, CL and J Marshall. 1976. Occupational sources of stress: A review of the literature relating to coronary heart disease and mental ill health. J Occup Psychol 49:11-28.

Dainoff, MG. 1982. Occupational Stress Factors in VDT Operation: A Review of Empirical Research in Behavior and Information Technology. London: Taylor & Francis.

Desmarais, MC, L Giroux, and L Larochelle. 1993. An advice-giving interface based on plan-recognition and user-knowledge assessment. Int J Man Mach Stud 39:901-924.

Dorard, G. 1988. Place et validité des tests ophthalmologiques dans l’étude de la fatigue visuelle engendrée par le travail sur écran. Grenoble: Faculté de médecine, Univ. de Grenoble.

Egan, DE. 1988. Individual differences in human-computer interaction. In Handbook of Human-Computer Interaction, edited by M Helander. Amsterdam: Elsevier.

Ellinger, S, W Karmaus, H Kaupen-Haas, KH Schäfer, G Schienstock, and E Sonn. 1982. 1982 Arbeitsbedingungen, gesundheitsverhalten und rheumatische Erkrankungen. Hamburg: Medizinische Soziologie, Univ. Hamburg.

Ericson, A and B Källén. 1986. An epidemiological study of work with video screens and pregnancy outcome: II. A case-control study. Am J Ind Med 9:459-475.

Frank, AL. 1983. Effects of Health Following Occupational Exposure to Video Display Terminals. Lexington, Ky: Department of Preventive Medicine and Environmental Health.

Frese, M. 1987. Human-computer interaction in the office. In International Review of Industrial and Organizational Psychology, edited by CL Cooper. New York: Wiley.

Frölén, H and N-M Svedenstål. 1993. Effects of pulsed magnetic fields on the developing mouse embryo. Biolelectromagnetics 14:197-204.

Fry, HJH. 1992. Overuse syndrome and the Overuse concept. Discussion Papers On the Pathology of Work-Related Neck and Upper Limb Disorders and the Implications for Treatment, edited by G Bammer. Working paper No. 32. Canberra: NCEPH, Australian National Univ.

Gaines, BR and MLG Shaw. 1986. From timesharing to the sixth generation: The development of human-computer interaction. Part I. Int J Man Mach Stud 24:1-27.

Gardell, B. 1971. Alienation and mental health in the modern industrial environment. In Society, Stress, and Disease, edited by L Levi. Oxford: OUP.

Goldhaber, MK, MR Polen, and RA Hiatt. 1988. The risk of miscarriage and birth defects among women who use visual display terminals during pregnancy. Am J Ind Med 13:695-706.

Gould, JD. 1988. How to design usable systems. In Handbook of Human Computer Interaction, edited by M Helander. Amsterdam: Elsevier.

Gould, JD and C Lewis. 1983. Designing for usability—Key principles and what designers think. In Proceedings of the 1983 CHI Conference On Human Factors in Computing Systems, 12 December, Boston. New York: ACM.

Grandjean, E. 1987. Ergonomics in Computerized Offices. London: Taylor & Francis.

Hackman, JR and GR Oldham. 1976. Motivation through the design of work: Test of a theory. Organ Behav Hum Perform 16:250-279.

Hagberg, M, Å Kilbom, P Buckle, L Fine, T Itani, T Laubli, H Riihimaki, B Silverstein, G Sjogaard, S Snook, and E Viikari-Juntura. 1993. Strategies for prevention of work-related musculo-skeletal disorders. Appl Ergon 24:64-67.

Halasz, F and TP Moran. 1982. Analogy considered harmful. In Proceedings of the Conference On Human Factors in Computing Systems. Gaithersburg, Md.: ACM Press.

Hartson, HR and EC Smith. 1991. Rapid prototyping in human-computer interface development. Interact Comput 3(1):51-91.

Hedge, A, WA Erickson, and G Rubin. 1992. Effects of personal and occupational factors on sick building syndrome reports in air-conditioned offices. In Stress and Well-Being At Work-Assessments and Interventions for Occcupational Mental Health, edited by JC Quick, LR Murphy, and JJ Hurrell Jr. Washington, DC: American Psychological Association.

Helme, RD, SA LeVasseur, and SJ Gibson. 1992. RSI revisited: Evidence for psychological and physiological differences from an age, sex and occupation matched control group. Aust NZ J Med 22:23-29.

Herzberg, F. 1974. The wise old Turk. Harvard Bus Rev (Sept./Oct.):70-80.

House, J. 1981. Work Stress and Social Support. Reading, Mass.: Addison-Wesley.

Hutchins, EL. 1989. Metaphors for interactive systems. In The Structure of Multimodal Dialogue, edited by DG Bouwhuis, MM Taylor, and F Néel. Amsterdam: North Holland.

Huuskonen, H, J Juutilainen, and H Komulainen. 1993. Effects of low-frequency magnetic fields on fetal development in rats. Biolelectromagnetics 14(3):205-213.

Infante-Rivard, C, M David, R Gauthier, and GE Rivard. 1993. Pregnancy loss and work schedule during pregnancy. Epidemiology 4:73-75.

Institut de recherche en santé et en sécurité du travail (IRSST). 1984. Rapport du groupe de travail sur les terminaux è écran de visualisation. Montréal: IRSST.

International Business Machines Corp. (IBM). 1991a. Systems Application Architecture. Common User Access Guide-Advanced Interface Design Reference. White Plains, NY.: IBM.

—. 1991b. Systems Application Architecture. Common User Access Guide to User Interface Design. White Plains, NY.: IBM.

International Labour Organization (ILO). 1984. Automation, Work Organisation and Occupational Stress. Geneva: ILO.

—. 1986. Special issue on visual display units. Cond Work Dig .

—. 1989. Working with Visual Display Units. Occupational Safety and Health Series, No. 61. Geneva: ILO.

—. 1991. Worker’s privacy. Part I: Protection of personal data. Cond Work Dig 10:2.

International Organization for Standardization (ISO). 1992. Ergonomic Requirements for Office Work With Visual Display Terminals (VDTs). ISO Standard 9241.Geneva: ISO.

Johansson, G and G Aronsson. 1984. Stress reactions in computerized administrative work. J Occup Behav 5:159-181.

Juliussen, E and K Petska-Juliussen. 1994. The Seventh Annual Computer Industry 1994-1995 Almanac. Dallas: Computer Industry Almanac.

Kalimo, R and A Leppanen. 1985. Feedback from video display terminals, performance control and stress in text preparation in the printing industry. J Occup Psychol 58:27-38.

Kanawaty, G. 1979. Introduction to Work Study. Geneva: ILO.

Karasek, RA, D Baker, F Marxer, A Ahlbom, and R Theorell. 1981. Job decision latitude, job demands, and cardiovascular disease. In Machine-Pacing and Occupational Stress, edited by G Salvendy and MJ Smith. London: Taylor & Francis.

Karat, J. 1988. Software evaluation methodologies. In Handbook of Human-Computer Interaction, edited by M Helander. Amsterdam: Elsevier.

Kasl, SV. 1978. Epidemiological contributions to the study of work stress. In Stress At Work, edited by CL Cooper and R Payne. New York: Wiley.

Koh, D, CL Goh, J Jeyaratnam, WC Kee, and CN Ong. 1991. Dermatologic complaints among visual display unit operators and office workers. Am J Contact Dermatol 2:136-137.

Kurppa, K, PC Holmberg, K Rantala, T Nurminen, L Saxén, and S Hernberg. 1986. Birth defects, course of pregnancy, and work with video display units. A Finnish case-referent study. In Work With Display Units 86: Selected Papers from the International Scientific Conference On Work With Display Units, May 1986, Stockholm, edited by B Knave and PG Widebäck. Amsterdam: North Holland.

Läubli, T, H Nibel, C Thomas, U Schwanninger, and H Krueger. 1989. Merits of periodic visual screening tests in VDU operators. In Work With Computers, edited by MJ Smith and G Salvendy. Amsterdam: Elsevier Science.

Levi, L. 1972. Stress and Distress in Response to Psychosocial Stimuli. New York: Pergamon Press.

Lewis, C and DA Norman. 1986. Designing for error. In User Centered System: New Perspectives On Human-Computer Interation, edited by DA Norman and SW Draper. Hillsdale, NJ.: Erlbaum Associates.

Lidén, C. 1990. Contact allergy: A cause of facial dermatitis among visual display unit operators. Am J Contact Dermatol 1:171-176.

Lidén, C and JE Wahlberg. 1985. Work with video display terminals among office employees. Scand J Work Environ Health 11:489-493.

Lindbohm, M-L, M Hietanen, P Kygornen, M Sallmen, P von Nandelstadh, H Taskinen, M Pekkarinen, M Ylikoski, and K Hemminki. 1992. Magnetic fields of video display terminals and spontaneous abortion. Am J Epidemiol 136:1041-1051.

Lindström, K. 1991. Well-being and computer-mediated work of various occupational groups in banking and insurance. Int J Hum Comput Interact 3:339-361.

Mantei, MM and TJ Teorey. 1989. Incorporating behavioral techniques into the systems development life cycle. MIS Q September:257-274.

Marshall, C, C Nelson, and MM Gardiner. 1987. Design guidelines. In Applying Cognitive Psychology to User-Interface Design, edited by MM Gardiner and B Christie. Chichester, UK: Wiley.

Mayhew, DJ. 1992. Principles and Guidelines in Software User Interface Design. Englewood Cliffs, NJ.: Prentice Hall.

McDonald, AD, JC McDonald, B Armstrong, N Cherry, AD Nolin, and D Robert. 1988. Work with visual display units in pregnancy. Brit J Ind Med 45:509-515.

McGivern, RF and RZ Sokol. 1990. Prenatal exposure to a low-frequency electromagnetic field demasculinizes adult scent marking behavior and increases accessory sex organ weights in rats. Teratology 41:1-8.

Meyer, J-J and A Bousquet. 1990. Discomfort and disability glare in VDT operators. In Work With Display Units 89, edited by L Berlinguet and D Berthelette. Amsterdam: Elsevier Science.

Microsoft Corp. 1992. The Windows Interface: An Application Design Guide. Redmond, Wash.: Microsoft Corp.

Monk, TH and DI Tepas. 1985. Shift work. In Job Stress and Blue Collar Work, edited by CL Cooper and MJ Smith. New York: Wiley.

Moran, TP. 1981. The command language grammar: A representation for the user interface of interaction computer systems. Int J Man Mach Stud 15:3-50.

—-. 1983. Getting into a system: External-internal task mapping analysis. In Proceedings of the 1983 CHI Conference On Human Factors in Computing Systems, 12-15 December, Boston. New York: ACM.

Moshowitz, A. 1986. Social dimensions of office automation. Adv Comput 25:335-404.

Murray, WE, CE Moss, WH Parr, C Cox, MJ Smith, BFG Cohen, LW Stammerjohn, and A Happ. 1981. Potential Health Hazards of Video Display Terminals. NIOSH Research Report 81-129. Cincinnati, Ohio: National Institute for Occupational Safety and Health (NIOSH).

Nielsen, CV and LPA Brandt. 1990. Spontaneous abortion among women using video display terminals. Scand J Work Environ Health 16:323-328.

—-. 1992. Fetal growth, preterm birth and infant mortality in relation to work with video display terminals during pregnancy. Scand J Work Environ Health 18:346-350.

Nielsen, J. 1992. The usability engineering life cycle. Computer (Mar.):12-22.

—-. 1993. Iterative user-interface design. Computer (Nov.):32-41.

Nielsen, J and RL Mack. 1994. Usability Inspection Methods. New York: Wiley.

Numéro spécial sur les laboratoires d’utilisabilité. 1994. Behav Inf Technol.

Nurminen, T and K Kurppa. 1988. Office employment, work with video display terminals, and course of pregnancy. Reference mothers’ experience from a Finnish case-referent study of birth defects. Scand J Work Environ Health 14:293-298.

Office of Technology Assessment (OTA). 1987. The Electronic Supervisor: New Technology, New Tensions. Washington, DC: US Government Printing Office.

Open Software Foundation. 1990. OSF/Motif Style Guide. Englewood Cliffs, NJ: Prentice Hall.

Ostberg, O and C Nilsson. 1985. Emerging technology and stress. In Job Stress and Blue Collar Work, edited by CL Cooper and MJ Smith. New York: Wiley.

Piotrkowski, CS, BFG Cohen, and KE Coray. 1992. Working conditions and well-being among women office workers. Int J Hum Comput Interact 4:263-282.

Pot, F, P Padmos, and A Brouwers. 1987. Determinants of the VDU operator’s well-being. In Work With Display Units 86. Selected Papers from the International Scientific Conference On Work With Display Units, May 1986, Stockholm, edited by B Knave and PG Widebäck. Amsterdam: North Holland.

Preece, J, Y Rogers, H Sharp, D Benyon, S Holland, and T Carey. 1994. Human Computer Interaction. Reading, Mass.: Addison-Wesley.

Quinter, J and R Elvey. 1990. The neurogenic hypothesis of RSI. Discussion Papers On the Pathology of Work-Related Neck and Upper Limb Disorders and the Implications for Treatment, edited by G Bammer. Working paper No. 24. Canberra: NCEPH, Australian National Univ.

Rasmussen, J. 1986. Information Processing and Man-Machine Interaction. An Approach to Cognitive Engineering. New York: North Holland.

Ravden, SJ and GI Johnson. 1989. Evaluating Usability of Human-Computer Interfaces: A Practical Approach. West Sussex, UK: E Horwood.

—. 1992. Systems Application Architecture: Common Communications Support. Englewood Cliffs, NJ: Prentice Hall.

Reed, AV. 1982. Error correcting strategies and human interaction with computer systems. In Proceedings of the Conference On Human Factors in Computing Systems Gaithersburg, Md.: ACM.

Rey, P and A Bousquet. 1989. Visual strain of VDT operators: The right and the wrong. In Work With Computers, edited by G Salvendy and MJ Smith. Amsterdam: Elsevier Science.

—. 1990. Medical eye examination strategies for VDT operators. In Work With Display Units 89, edited by L Berlinguet and D Berthelette. Amsterdam: Elsevier Science.

Rheingold, HR. 1991. Virtual Reality. New York: Touchstone.

Rich, E. 1983. Users are individuals: Individualizing user models. Int J Man Mach Stud 18:199-214.

Rivas, L and C Rius. 1985. Effects of chronic exposure to weak electromagnetic fields in mice. IRCS Med Sci 13:661-662.

Robert, J-M. 1989. Learning a computer system by unassisted exploration. An example: The Macintosh. In MACINTER II Man-Computer Interaction Research, edited by F Klix, N Streitz, Y Warren, and H Wandke. Amsterdam: Elsevier.

Robert, J-M and J-Y Fiset. 1992. Conception et évaluation ergonomiques d’une interface pour un logiciel d’aide au diagnostic: Une étude de cas. ICO printemps-été:1-7.

Roman, E, V Beral, M Pelerin, and C Hermon. 1992. Spontaneous abortion and work with visual display units. Brit J Ind Med 49:507-512.

Rubino, GF. 1990. Epidemiologic survey of ocular disorders: The Italian multicentric research. In Work With Display Units 89, edited by L Berlinguet and D Berthelette. Amsterdam: Elsevier Science.

Rumelhart, DE and DA Norman. 1983. Analogical processes in learning. In Cognitive Skills and Their Acquisition, edited by JR Anderson. Hillsdale, NJ: Lawrence Erlbaum.

Ryan, GA and M Bampton. 1988. Comparison of data process operators with and without upper limb symptoms. Community Health Stud 12:63-68.

Ryan, GA, JH Mullerworth, and J Pimble. 1984. The prevalence of repetition strain injury in data process operators. In Proceedings of the 21st Annual Conference of the Ergonomics Society of Australia and New Zealand. Sydney.

Sainfort, PC. 1990. Job design predictors of stress in automated offices. Behav Inf Technol 9:3-16.

—-. 1991. Stress, job control and other job elements: A study of office workers. Int J Ind Erg 7:11-23.

Salvendy, G. 1992. Handbook of Industrial Engineering. New York: Wiley.

Salzinger, K and S Freimark. 1990. Altered operant behavior of adult rats after perinatal exposure to a 60-Hz electromagnetic field. Biolelectromagnetics 11:105-116.

Sauter, SL, CL Cooper, and JJ Hurrell. 1989. Job Control and Worker Health. New York: Wiley.

Sauter, SL, MS Gottlieb, KC Jones, NV Dodson, and KM Rohrer. 1983a. Job and health implications of VDT use: Initial results of the Wisconsin-NIOSH study. Commun ACM 26:284-294.

Sauter, SL, MS Gottlieb, KM Rohrer, and NV Dodson. 1983b. The Well-Being of Video Display Terminal Users. An Exploratory Study. Cincinnati, Ohio: NIOSH.

Scapin, DL. 1986. Guide ergonomique de conception des interfaces homme-machine. Rapport de recherche no. 77. Le Chesnay, France: INRIA.

Schnorr, TM, BA Grajewski, RW Hornung, MJ Thun, GM Egeland, WE Murray, DL Conover, and WE Halperin. 1991. Video display terminals and the risk of spontaneous abortion. New Engl J Med 324:727-733.

Shepherd, A. 1989. Analysis and training in information technology tasks. In Task Analysis for Human-Computer Interaction, edited by D Diaper. Chichester: E Horwood.

Shneiderman, B. 1987. Designing the User Interface: Strategies for Effective Human-Computer Interaction. Reading, Mass.: Addison-Wesley.

Sjödren, S and A Elfstrom. 1990. Eye discomfort among 4000 VDU users. In Work With Display
Units 89, edited by L Berlinguet and D Berthelette. Amsterdam: Elsevier Science.

Smith, MJ. 1987. Occupational stress. In Handbook of Ergonomics/Human Factors, edited by G Salvendy. New York: Wiley.

Smith, MJ and BC Amick. 1989. Electronic monitoring at the workplace: Implications for employee control and job stress. In Job Control and Worker Health, edited by S Sauter, J Hurrel, and C Cooper. New York: Wiley.

Smith, MJ, P Carayon, and K Miezio. 1987. VDT technology: Psychosocial and stress concerns. In Work With Display Units, edited by B Knave and PG Widebäck. Amsterdam: Elsevier Science.

Smith, MJ and P Carayon-Sainfort. 1989. A balance theory of job design for stress reduction. Int J Ind Erg 4:67-79.

Smith, MJ, BFG Cohen, LW Stammerjohn, and A Happ. 1981. An investigation of health complaints and job stress in video display operations. Hum Factors 23:387-400.

Smith, MJ, P Carayon, KH Sanders, S-Y Lim, and D LeGrande. 1992a. Electronic performance monitoring, job design and worker stress. Appl Ergon 23:17-27.

Smith, MJ, G Salvendy, P Carayon-Sainfort, and R Eberts. 1992b. Human-computer interaction. In Handbook of Industrial Engineering, edited by G Salvendy. New York: Wiley.

Smith, SL and SL Mosier. 1986. Guidelines for Designing User Interface Software. Report ESD-TR-278. Bedford, Mass.: MITRE.

South Australian Health Commission Epidemiology Branch. 1984. Repetition Strain Symptoms and Working Conditions Among Keyboard Workers Engaged in Data Entry or Word Processing in the South Australian Public Service. Adelaide: South Australian Health Commission.

Stammerjohn, LW, MJ Smith, and BFG Cohen. 1981. Evaluation of work station design factors in VDT operations. Hum Factors 23:401-412.

Stellman, JM, S Klitzman, GC Gordon, and BR Snow. 1985. Air quality and ergonomics in the office: Survey results and methodologic issues. Am Ind Hyg Assoc J 46:286-293.

—-. 1987a. Comparison of well-being among non-machine interactive clerical workers and full-time and part-time VDT users and typists. In Work With Display Units 86. Selected Papers from the International Scientific Conference On Work With Display Units, May 1986, Stockholm, edited by B Knave and PG Widebäck. Amsterdam: North Holland.

—-. 1987b. Work environment and the well-being of clerical and VDT workers. J Occup Behav 8:95-114.

Strassman, PA. 1985. Information Payoff: The Transformation of Work in the Electronic Age. New York: Free Press.

Stuchly, M, AJ Ruddick, et al. 1988. Teratological assessment of exposure to time-varying magnetic fields. Teratology 38:461-466.

Sun Microsystems Inc. 1990. Open Look. Graphical User Interface Application Style Guidelines. Reading, Mass.: Addison-Wesley.

Swanbeck, G and T Bleeker. 1989. Skin problems from visual display units: Provocation of skin symptoms under experimental conditions. Acta Derm-Venereol 69:46-51.

Taylor, FW. 1911. The Principles of Scientific Management. New York: Norton & Co.

Thimbleby, H. 1990. User Interface Design. Chichester: ACM.

Tikkanen, J and OP Heinonen. 1991. Maternal exposure to chemical and physical factors during pregnancy and cardiovascular malformations in the offspring. Teratology 43:591-600.

Tribukait, B and E Cekan. 1987. Effects of pulsed magnetic fields on embryonic development in mice. In Work With Display Units 86: Selected Papers from the International Scientific Conference On Work With Display Units, May 1986, Stockholm, edited by B Knave and PG Widebäck. Amsterdam: North Holland.

Wahlberg, JE and C Lidén. 1988. Is the skin affected by work at visual display terminals? Dermatol Clin 6:81-85.

Waterworth, JA and MH Chignell. 1989. A manifesto for hypermedia usability research. Hypermedia 1:205-234.

Westerholm, P and A Ericson. 1986. Pregnancy outcome and VDU work in a cohort of insurance clerks. In Work With Display Units 86. Selected Papers from the International Scientific Conference On Work With Display Units, May 1986, Stockholm, edited by B Knave and PG Widebäck. Amsterdam: North Holland.

Westlander, G. 1989. Use and non-use of VDTs—Organization of terminal work. In Work With Computers: Organizational, Management, Stress and Health Aspects, edited by MJ Smith and G Salvendy. Amsterdam: Elsevier Science.

Westlander, G and E Aberg. 1992. Variety in VDT work: An issue for assessment in work environment research. Int J Hum Comput Interact 4:283-302.

Wickens, C. 1992. Engineering Psychology and Human Performance. New York: Harper Collins.

Wiley, MJ and P Corey. 1992. The effects of continuous exposure to 20-khz sawtooth magnetic fields on the litters of CD-1 mice. Teratology 46:391-398.

Wilson, J and D Rosenberg. 1988. Rapid prototyping for user interface design. In Handbook of Human-Computer Interaction, edited by M Helander. Amsterdam: Elsevier.

Windham, GC, L Fenster, SH Swan, and RR Neutra. 1990. Use of video display terminals during pregnancy and the risk of spontaneous abortion, low birthweight, or intrauterine growth retardation. Am J Ind Med 18:675-688.

World Health Organization (WHO). 1987. Visual Display Terminals and Workers’ Health. Geneva: WHO.

—-. 1989. Work with visual display terminals: Psychosocial aspects and health. J Occup Med 31:957-968.

Yang, C-L and P Carayon. 1993. Effects of job demands and job support on worker stress: A study of VDT users. Behav Inf Technol .

Young, JE. 1993. Global Network. Computers in a Sustainable Society. Washington, DC: Worldwatch Paper 115.

Young, RM. 1981. The machine inside the machine: Users’ models of pocket calculators. Int J Man Mach Stud 15:51-85.

Zecca, L, P Ferrario, and G Dal Conte. 1985. Toxicological and teratological studies in rats after exposure to pulsed magnetic fields. Bioelectrochem Bioenerget 14:63-69.

Zuboff, S. 1988. In the Age of the Smart Machine: The Future of Work and Power. New York: Basic Books.