Observation is the active acquisition of information from a primary source. In living beings, observation employs the
senses. In science, observation can also involve the recording of data via the use of instruments. The term may also refer to any
data collected during the scientific activity. Observations can be
qualitative, that is, only the absence or presence of a property is noted, or quantitative if a numerical value is attached to the observed phenomenon by
counting or
measuring.