The Straw Man fallacy is committed when a person simply ignores a person's actual position and substitutes a distorted, exaggerated or misrepresented version of that position. This sort of "reasoning" has the following pattern:
1. Person A has position X.
2. Person B presents position Y (which is a distorted version of X).
3. Person B attacks position Y.
4. Therefore X is false/incorrect/flawed.
This sort of "reasoning" is fallacious because attacking a distorted version of a position simply does not constitute an attack on the position itself. One might as well expect an attack on a poor drawing (straw man) of a person to hurt the person.
The straw man fallacy is when you misrepresent someone else's position so that it can be attacked more easily, knock down that misrepresented position, then conclude that the original position has been demolished. It's a fallacy because it fails to deal with the actual arguments that have been made.
To "set up a straw man" or "set up a straw-man argument" is to create a position that is easy to refute, then attribute that position to the opponent.
AR version: "To believe that animals should have rights because they suffer you have to know with absolute certainty they have feelings. To know this with absolute certainty you need to communicate with an animals. Since you obviously haven't, your position is indefensible."
Show that the opposition's argument has been misrepresented by showing that the opposition has a stronger argument. Describe the stronger argument