According to Keeley, Stuart M. and Neil M. Brown, Asking the Right Questions, evidence is information used by the writer or speaker that helps to validate certain claims, or reasons, he/she has made in an argument. (p. 91)
Personal Experience: Using things from your past experiences as evidence to back an argument. A possible problem with this one is what Keeley and Brown call “hasty generalization,” for example, if this is the case with my experience, then this must be the case for every experience that has these parameters
Case Examples: Vivid stories of events to help support a claim and to get the audience interested in whatever is being argued. While this can be good to use in helping an audience to understand the issue, this isn’t hard evidence.
Testimonials: These are reviews of events. Some can be false, especially if seeing them on the internet.
Appeals to Authority: This kind of evidence is better then the types that precede this type of evidence. You are invoking the words or works of an expert in a certain field. Trouble is the expert might be wrong, or experts contradict themselves withing the same field of expertise.
The article I read, Why Questions (Good or Bad) Matter, by Marcello Fiocco, is an article of how important it is to ask questions. He used three types of evidence in his article. Spoke from experience, “whose job it is to ask questions” (Fiocco), as a professor of philosophy and he spoke of his children saying, “I say this as a father of two small children with a tendency to ask questions for which the answers are clearly not the goal.” Case example, where he spoke of a girl who asked seemingly stupid questions about the origins of math on her tiktok page where everybody made fun of her for doing so. Except when (appealing to authority) the experts came and said that she wasn’t stupid and couldn’t really give her a straight answer to her philosophical questions because they, the experts, didn’t know. I thought that the case evidence was relevant and interesting, made me that much more engaged in the topic and got me thinking of “is there stupid questions? Or should I have more tolerance for people and their questions?” The evidence fit the argument well. Now for the personal experience evidence; I thought this could have been left out and it would have been a better argument for it. His assumption that I care for his experience/opinion or think him an expert on the issue because of it was wrong. Fiocco’s appeal to my emotions with his opinion, “I believe that asking questions should be of the utmost importance to anyone who cares about themselves or others,” was actually kind of insulting and made me angry. If he would have just stuck with the case evidence and the experts, other than himself, the article would have been awesome.
Fiocco, Marcello, Why Questions (Good and Bad) Matter, The conversation, 2 November 2020, https://theconversation.com/why-questions-good-and-bad-matter-147412