When you use the availability heuristic, you are: mistaking visual images and other forms of mental representations for reality. assuming that something is typical of its class. making frequency estimates based on the ease with which things come to mind. overcoming mental set?

When you use the availability heuristic, you are basing your judgments on the extent to which an event matches your expectations 
When using availability heuristic, we will rely only on specific examples that are familiar to us. If this used in argument, our basic argument will only come across as subjective or biased.

To be completely honest I have no idea what that means