|1. Observer is ....|
2. Exercise participant who watches selected segments as they unfold while remaining separate from role player activities.
Notes (1) : Observers play a crucial role in the debriefing and reporting process after an exercise. The term is also used for "VIP observers", who usually visit the exercise for only a short time, largely for internal or external PR purposes, and do not take part in the debrief.
(Source: ISO 22390:2011 - Societal Security - Guidelines for Exercises and Testing) - clause 3.19