Biology Reference
In-Depth Information
will be discussed within the context of a theoretical model of SA, citing the
value of conducting an SA requirement analysis and designing SA-oriented
systems.
4.2 Theoretical Model of Situation Awareness
According to the theoretical model of SA proposed by Endsley (1995), SA
can be defined as “the perception of elements in the environment within
a volume of time and space, the comprehension of their meaning, and the
projection of their status in the near future.” This definition highlights three
levels or stages of SA formation: perception, comprehension, and projec-
tion (see Figure 4.1). Level 1 SA (perception) involves the sensory detection
of significant environmental cues. Perception is an active process whereby
individuals extract salient cues from their environment. Level 2 SA (com-
prehension) involves integrating this information in working memory to
understand how the information will impact the individual's goals and
objectives (Salas et al. 1995). Level 3 SA (projection) involves extrapolating
this information forward in time to determine how it will affect future states
System capability
Interface design
Stress & workload
Complexity
Automation
Ta sk/System Factors
Feedback
SITUAT ION AWARENESS
Perception
of Elements
in Current
Situation
Level 1
Projection
of Future
Status
Comprehension
of Current
Situation
Level 2
State of the
Environment
Performance
of Actions
Decision
Level 3
Individual Factors
Information Processing
Mechanisms
Goals & objectives
Preconceptions
(Expectations)
Long Te rm
Memory Stores
Automaticity
Abilities
Experience
Training
Figure 4.1
Theoretical model of situation awareness. (Adapted from Endsley 1995, Toward a theory of
situation awareness in dynamic systems,
Human Factors
37[1]: 32-64.)
