Non sequitur ('it don't follow'): The writer's conclusion is not necessarily a logical result of the facts. An example of a non sequitur occurs when you conclude, "Professor Smith is a famous chemist, so he will be a brilliant chemistry teacher." As you may have realized by now, the fact that someone knows a subject well does not automatically mean that he or she can communicate the information clearly in a classroom; hence, the conclusion is not neccessarily vaild.