A qualification opens a door that daily judgment still has to walk through.

Credentials answer one question and no others. They say somebody met a standard on a particular day, which is enough to let them start, and say nothing about what they will do on a Tuesday when the situation does not match the textbook. Competence is a series of small decisions made under pressure, none of which appear on the certificate.

Holding the qualification, keep asking whether your daily judgment is improving, since that is the part nobody will test again. If you are choosing someone, ask how they handled a case that went wrong. The answer tells you more than the letters after the name.