I just learned of a fascinating term, coined by Nobel Prize-winners Daniel Kahneman and Amos Tversky.
availability bias - the tendency to judge the likelihood of an event by how readily examples can be brought to mind
Can we provide examples?
(Apparently this led to several related terms: informational, reputational and availability cascades. My research is continuing, and I hope others will join me. As of now my only further data is that "availability cascade" was coined by Cass Sunstein and Timur Kuran in a 1999 Stanford Law Review article.)
When phone polls are conducted, there is an inherent availability bias, that is, only people with phones are sampled! This can be an instance of selection bias, which is selecting a sample which is representative of the group you are studying, that is, selecting people who have phones(and are at home to answer the phone when the call is made, and who are willing to answer the questions). Another example of availability bias is reports of a truck driver driver poorly. Obviously, no one is going to call up and say "he signaled properly and was a very courteous driver".
One sees this a lot in mathematics. Start naming numbers, and you see that most numbers are rational numbers, 0, 4, 5/6, etc. It is very difficult to find examples against this, like the sqrt(2). However, given a random number between any two points, the probability that a rational number is selected is 0.
In response to 9-11 we have beefed up airport security, giving airports and planes much more attention than other targets which may be far more vulnerable. Why? Because 9-11 comes to mind so easily? We are very aware of terrorist attacks involving airplanes, and tend to view them as the more-likely attacks, meriting greater prevention.