a convincing test of a new product
convincing
/kən-ˈvin(t)-siŋ/
adjective
satisfying or assuring by argument or proof
having power to convince of the truth, rightness, or reality of something : plausible
verb
to bring (as by argument) to belief, consent, or a course of action : persuade
to overcome by argument
overpower, overcome
convinced himself that she was all right