Arguments can be looked at in various ways. We can notice their content, what the statements are about. We can also pay attention to their form or structure, how they are set up and the relationships among the various statements. We can try to determine how well the premise statement(s) support the conclusion statement. And we can ask whether the premise statements are true or false. In fact, for a critical interpretation and evaluation of any particular argument we must do all of these.
There are two critical criteria to consider when evaluating an argument:
The second criterion is often more difficult to determine since it requires some sort of outside verification. Often the verification will be done by making observations under controlled circumstances (performing experiments) or drawing upon the experience of all human kind (using well-established theories).
In order for an argument to establish the truthfulness of a conclusion it must be a sound argument, the premises must deductively lead to the conclusion and the premises must be true.
Brief summary of logical fallacies.