observational vs experimental

observational and experimental both are adjectives.

Word	Noun	Adjective	Verb	Adverb
observational	No	Yes	No	No
experimental	No	Yes	No	No

As adjectives, observational and experimental are synonyms defined as:

Other synonyms of observational include data-based.

observational (adjective)	experimental (adjective)
relying on observation or experiment	relating to or based on experiment
	relying on observation or experiment
	of the nature of or undergoing an experiment