The structure of an argument shows any subarguments within it. The purposes or goals of explanations and arguments are different. Every argument contains at least two statements. Arguments with wide scope must have high certainty. An ambiguous or vague statement is always an acceptable premise.
Common knowledge is a bad reason to accept a premise.
Appeal to authority is a fallacy of relevance. Inductive arguments are always based on observations of the world. If an argument's premises are true, it must be a good argument. Good analogies are always relevant. An appeal to popularity has negative relevance.