- Observation Ob`ser*va"tion, n. [L. observatio: cf. F.
1. The act or the faculty of observing or taking notice; the
act of seeing, or of fixing the mind upon, anything.
My observation, which very seldom lies. --Shak. [1913 Webster]
5. (Science) (a) The act of recognizing and noting some fact or occurrence in nature, as an aurora, a corona, or the structure of an animal. (b) Specifically, the act of measuring, with suitable instruments, some magnitude, as the time of an occultation, with a clock; the right ascension of a star, with a transit instrument and clock; the sun's altitude, or the distance of the moon from a star, with a sextant; the temperature, with a thermometer, etc. (c) The information so acquired; as, to record one's observations carefully. [1913 Webster]
Note: When a phenomenon is scrutinized as it occurs in nature, the act is termed an observation. When the conditions under which the phenomenon occurs are artificial, or arranged beforehand by the observer, the process is called an experiment. Experiment includes observation. [1913 Webster]
The Collaborative International Dictionary of English. 2000.