I do believe that for the most part bias should be avoided when using supporting material. If a speaker is biased, it might be hard to believe their supporting material because they only have opinions for one side. Also if a speaker is biased, they might only pick supporting information that will defend and back up their claim. As a speaker, I think it is a good idea to defend your opinion, but it is also important to mention the opposing side of your argument. This shows that you aren’t completely biased, and that you are open to listening to different opinions. However, I also think that bias can be unavoiable if someone is talking about a personal experience or something that happened to them. To close, for the most part in speaking, bias should be avoided, but there are times that it can also be unavoidable.
It's true that it's harder to believe someone when they only mention one side of an argument and don't acknowledge the other.
I loved how you talked about how you can see both sides. I agree that it should be avoided but it can for sure be hard to avoid in everyday encounters.