The author's excellent 'powers of observation' [=ability to notice and pay close attention to things] are evident in the book's detailed descriptions.
The plants seem to have recovered from the disease, but they are still 'under observation'. [=someone is watching them carefully]
They're keeping him at the hospital 'for observation' [=so that doctors can watch him carefully] for another few days.
(..) These are my books. This is my door. Please close it behind you, goodbye. You're doing work in quantum loop corrections. - Keen observation, goodbye. - You see where you went wrong, don't you? - Leonard. - Ha. - Yeah? - Get him out. (..)2008 TvShow: The Big Bang Theory Title: The Jerusalem Duality Season: 1 Episode 12