Search and Rescue (SAR) missions around the world can be as different as the SAR organizations that undertake them.
Mastery in SAR, therefore, requires generalizing mission strategies in order to find and improve upon what they have in common.
Based on a combination of years of searching, instructing and evaluating, I've captured the principal factors of success common to searching for lost and missing people.
The above techniques primarily use interior void searching as a reference point.
Because of the complexity and variability interior spaces present for searchers, they provide an ideal learning environment to optimize search skills.