Theoretical Underpinnings of Situation Awareness, A Critical Review

The enhancement of operator situation awareness (SA) has become a major designgoal for those developing operator interfaces, automation concepts and training programs ina wide variety of fields, including aircraft, air traffic control, power plants, and advancedmanufacturing systems. This dramatic growth in interest in SA, beginning in the mid-1980’s and accelerating through the 1990’s, was spurred on by many factors, chief amongthem the challenges of a new class of technology. One can easily see that situation awareness has always been needed in order forpeople to perform tasks effectively. Prehistoric man undoubtedly needed to be aware ofmany cues in his environment in order to successfully hunt and keep from being hunted.For many years, having good situation awareness was largely a matter of training andexperience — learning the important cues to watch for and what they meant. With the advent of the machine age, our emphasis shifted to creating a new class oftools to help people perform tasks, largely those physical in nature. The computer age andnow the information age have followed rapidly on the heals of basic mechanization. Thetools provided are no longer simple; they are amazingly complex, focused on not justphysical tasks, but elaborate perceptual and cognitive tasks as well. The pilot of today’saircraft, the air traffic controller, the power plant operator, the anesthesiologist: all mustperceive and comprehend a dazzling array of data which is often changing very rapidly. Ihave taken to calling this challenge the information gap (Figure 1).Today’s systems are capable of producing a huge amount of data, both on the statusof their own components, and on the status of the external environment. Due toachievements in various types of datalink and internet technologies, systems can alsoprovide data on almost anything anywhere in the world. The problem with today’s systemsis not a lack of information, but finding what is needed when it is needed.Unfortunately, in the face of this torrent of data, many operators may be even lessinformed than ever before. This is because there is a huge gap between the tons of databeing produced and disseminated and people’s ability to find the bits that are needed andprocess them together with the other bits to arrive at the actual information that is requiredfor their decisions. This information must be integrated and interpreted correctly as well; afrequently tricky task. This problem is real and ongoing, whether the job is in the cockpitor behind a desk. It is becoming widely recognized that more data does not equal moreinformation. Issues of automation and “intelligent systems” have frequently onlyexacerbated the problem, rather than aided it (Endsley & Kiris, 1995; Sarter & Woods,1995).The criteria for what we are seeking from system designs have correspondinglychanged. In addition to designing systems that provide the operator with the neededinformation and capabilities, we must also insure that it is provided in a way that is useablecognitively as well as physically. We want to know how well the system design supportsthe operator’s ability to get the needed information under dynamic operational constraints.(i.e. How well does it bridge the information gap?) This design objective and measure ofmerit has been termed situation awareness.