Chapter 16 talks about the use and importance of evidence in your arguments. Coming from engineering stand point evidence is everything. You cannot just go around saying anything and expect people to believe you, there must be some information proving that it is true. Evidence can come in any amount of forms, such as pathos, and ethos. Or it could just be some sort of data. For example during the earlier ages of man we thought that the sun revolved around the earth. It was not until someone was able to point out the evidence that there are in fact several planets revolving the sun including earth. When I think of evidence I think of proving something. I can talk about a fact and how great I know it, but people will not necessarily listen unless I proved some information to prove it is a fact. Or in a court case when somebody is shot and killed, the gun is evidence, and you prove that this was the gun he or she was shot with. There are two types of evidence they covered first hand, and second hand evidence. First hand evidence would be obviously first hand. Some examples of first hand evidence are observations, experiments, and interviews or surveys. Second hand evidence would being using sources such as peer review articles, or papers other people have already written and proved.
Although evidence is very important to an argument, it must be credible. For example if a hobo tells you the sun is 120 degrees because it is 120 degrees outside it is not very credible. Although there is some observation, there is not scientific reasoning making the earth’s temperature comparable to the suns temperature. Although many teachers bag on Wikipedia it is a great source of true facts, because although anyone can post it goes through hundreds of reviews before it is kept permanently. Many people use library to research information, which it is important to pick out research books and not just a story.