Experience/Credibility
Experience underpins credibility. Of all the inputs into competence, or credibility, such as knowledge, skills, attitude, personality, or experience – experience is the one that is hardest to fake. It is also the one that relies on other humans for verification. It’s like if a tree falls in the forest, and there’s no one there to hear it, does it make a sound? If you gain experience, but no one knows about it, does it matter?
Every test of someone’s competence includes input of experience. It’s a rare interview that does not delve into someone’s past in order to verify abilities.