Repairing Arguments

There are guidelines to repairing an argument. But they need to satisfy the points in the textbook. The argument needs to become stronger, the premise needs to become plausible, and the premise is more plausible than the conclusion. For example you could say, "Car mechanics know how to fix cars. Doug is a mechanic, so he knows how to fix my car." This argument is lacking somehow. We know that car mechanics fix cars and we know that Doug is a mechanic. It lacks the right information that Doug is a car mechanic. Without the adjective describing what kind of mechanic Doug is. He could be a utilities mechanic. Those kinds of mechanics for sure are not specialized in cars. This argument would be valid with the description of what kind of mechanic Doug is. This argument satisfies the three criteria with the modification. It becomes more vaid. And premises are descriptive and therefore plausible. And the premise was already more plausible than the conclusion.