observation vs measurement

observation and measurement both are nouns.

Word	Noun	Adjective	Verb	Adverb
observation	Yes	No	No	No
measurement	Yes	No	No	No

As nouns, measurement is a hypernym of observation; that is, measurement is a word with a broader meaning than observation:

observation: the act of making and recording a measurement
measurement: the act or process of assigning numbers to phenomena according to a rule

Other hypernyms of observation include measure, measuring, mensuration.

observation (noun)	measurement (noun)
the act of observing; taking a patient look	the act or process of assigning numbers to phenomena according to a rule
the act of making and recording a measurement
the act of noticing or paying attention
facts learned by observing
a remark expressing careful consideration