open-ended vs changeable

open-ended and changeable both are adjectives.

Word	Noun	Adjective	Verb	Adverb
open-ended	No	Yes	No	No
changeable	No	Yes	No	No

open-ended (adjective)	changeable (adjective)
allowing for future changes or revisions	such that alteration is possible; having a marked tendency to change
allowing for a spontaneous response	capable of or tending to change in form or quality or nature
without fixed limits or restrictions	varying in color when seen in different lights or from different angles
	subject to change