In this fascinating and important paper, the author shows how a chronic failure of people working in traditional disciplines (software engineers, cognitive ergonomists, and sociologists) to understand the workings of a paper-based system have resulted in the design of “paperless” systems that fail to meet the needs of a user community, and are therefore rejected, defeated, or circumvented by the users. The paper is narrowly focused on air traffic control, but the lessons presented apply broadly, even to the office environment.
Since shortly after World War II, air traffic controller practices have been based on a combination of observing radar displays and manipulating paper “flight strips” containing both printed data and annotations made by the controllers. Numerous attempts have been made to modernize air traffic control by automating the functions implemented by the paper strips. All have failed, sometimes without the knowledge of the designers or management, who were unaware that the controllers continued to use the old paper system.
MacKay reports the results of a four-month study of operations at the Athis-Mons (Paris) air traffic control center, followed by a comparative study of practices at seven other centers in France and the Netherlands. We learn that paper flight strips are an essential medium for social interaction between controllers, fostering cooperation, information interchange, and a system of checks and balances that reduces the error rate. Information is communicated by such actions as handing a strip to another controller, throwing it, placing it in the direct focus view of another controller, placing it in the peripheral vision field of another controller, or manually annotating a strip within sight of another controller. Even background noise generated by the paper system conveys important information to controllers. None of these effects has been achieved by any attempt to automate the handling of information on the strips.
The author concludes that using computers to augment the functions of paper flight strips, rather than replacing them, may result in usable enhancements to the current systems.