1. If the universe had been created by a supernatural being, we would see order and organization everywhere. And we do see order, not randomness -- so it's clear that the universe had a creator.

This is a case of affirming the consequent. This is clear from the form of the argument, which is If U, then O; O; therefore U.

2. Either we take decisive military action against Iraq, or we will one day be attacked with chemical and biological weapons in the U.S.

False dichotomy. There are probably other ways to avoid such attacks -- even if you think that doing something about the current Iraqi leadership is necessary, you might think that there are other options than military action.

3. The bicycle is made entirely of low mass components, and is therefore very lightweight.

Composition. Even if it is true that each of the parts of the bicycle has a low mass, the bicycle might have large mass -- for example if is has a large number of such parts.

4. Princeton graduates score much higher on the GREs than do graduates from Duke. Mike is from Princeton, so it's obvious that he'll do better than Sarrah on the GREs, since she is from Duke.

Division. Supposing that on average Princeton grads do better on this exam, it does not follaw that each graduate from princeton does better than every grduate from Duke. The properties of the whole are being attributed to the parts inappropriately.

5. Interviewer: "Your resume looks impressive but I need another reference."

Bill: "Jill can give me a good reference."

Interviewer: "Good. But how do I know that Jill is trustworthy?"

Bill: "Certainly. I can vouch for her."

Begging the question. The arguer is trying to establish his own credentials, and gives as a reference someone whose only known credential is that the arguer vouches for her. Clearly, if you are suspicious of the arguer to begin with, you will not find this line of support at all persuasive.

6. The professor said that if we didn't do the homework, we would not pass. I did all the homework, and so I should have passed. But she still gave me an F. So I'm going to complain to the dean.

Denying the antecedent. The argument is If ~H, then ~P; H; therefore P.