The entire procedure of induction lacks formal proof and is unable to provide conclusive or absolutely certain conclusion.
There can be higher degree of probolilty of the conclusion if it coheres with more and more established facts.
Time to time new Genralisations are established and accepted. A generalization is suggested like a hypothesis so there is the need of verification for the confirmation of the hypothesis.
Thus, verifiability is the important criterion of a legitimate hypothesis. It is also the most important condition for the proof of the hypothesis.