The art of thinking · 6 · Judgment, action and error
Situation awareness
Also known as: Situational awareness, SA
German: Situationsbewusstsein
In human factors, situation awareness is, in Mica R. Endsley’s model, the perception of the elements in the environment within a volume of time and space (level 1), the comprehension of their meaning (level 2) and the projection of their status in the near future (level 3), as the basis for decisions in dynamic systems.
- Cognitive psychology
- Human factors
In one sentence
Situation awareness (Endsley, 1995) is perceiving what is going on, understanding what it means and projecting what happens next.
Example
An operator sees that the filler’s tank level is falling (perception), understands that the infeed valve is blocked (comprehension) and expects the filler to stop within two minutes (projection).
What the research shows
Mica R. Endsley (1995) presented situation awareness as a state of knowledge that supports decision making in dynamic domains such as aviation, process control and military command. She described three levels — perception, comprehension and projection — and identified attention and working memory as the main limits, with mental models and goal-directed processing as mechanisms that help operators overcome them. She also discussed how design features, workload, stress, system complexity and automation affect situation awareness, and introduced a taxonomy of situation awareness errors. Measures include freeze-probe techniques, in which a simulation is paused and operators answer questions about the situation.
Evidence status
Situation awareness is a widely used construct in human factors, with established measurement methods and many applied studies. It is also contested: Sidney Dekker and Erik Hollnagel (2004) argued that it functions as a “folk model” that renames phenomena without explaining them and invites blaming operators for a “loss of situation awareness” after an accident. Alternative views treat situation awareness as distributed across teams and artifacts. The construct describes the operator's understanding; it is not a property of the system design that can be certified.
How it applies
Alarm texts, operator documentation and emergency information support awareness at all three levels: what is happening, what it means, what will happen next. The glossary “Applied cognitive psychology for information use” covers the design side, for example hazard perception. On machines and plants, situation awareness depends above all on the human-machine interface (HMI) and on alarm management; documentation supports, but does not replace, these measures.
External references
How to read this pool
Entries, context cards and transitional topics
The art of thinking explains ways of thinking — where a method comes from, what it asks of you and how it was adapted later. You meet four kinds of content here, each with its own job:
- Glossary entry
- Defines one concept or method of thinking: its origin, an example and how it relates to neighboring ideas. “X vs. Y” sections set two methods side by side.
- Context card of the art of thinking
- A short, self-contained answer to one question about a way of thinking — its lineage, its steps, its limits. These cards are listed on The art of thinking only.
- Transitional topicBridges both pools
- A context card that bridges both pools: it shows how a way of thinking was adapted into documentation, analysis or quality practice. It sits with the reference context cards and is marked as transitional wherever it appears.
- Reference entry or context card
- Belongs to the Glossary & Norms Space on regulation, norms and engineering. Entries here link to one only where a method is also an established tool of documentation or quality work, such as the five whys or a user’s mental model.