Evidence is used in a text to substantiate and strengthen its argument and hypothesis. Thus, a text with clear evidence is usually less susceptible to dispute. For example, scientifically proven facts, statistics, and expert opinion are examples of evidence that gives credibility to your text. If you are going to speak to an audience that tends to disagree with your text, you should use the evidence as it is usually undisputed. However, you should use evidence for evidence only and not for other reasons. Thus, the evidence should refer directly to the subject, you should not use evidence just to increase your text. The evidence should be associated with the argument, you should not put evidence that is not associated with your subject.
Explanation: If you can not summarize your passage, you do not have a clear thesis. A thesis is your purpose. It is at the beginning of your essay, and is the one sentence that explains what the rest of the essay is. Remember, a thesis is like the backbone of the essay, without it, your essay does not make sense.
