Why does the inclusion of an author make a source more credible? You can learn if others share the same opinions as the author.
You can research more about his/her frame of reference and bias.
You can contact the author to ask questions.
You can attack hem/her personally.

How did the russian revolution impact world war i? a) the russians required the allied powers to come to their aid and defeat the radical groups. b) the russians pulled out from the war, enabling the germans to focus on the western front. c) the russians created new technological advancements that were used by the allied powers to win. d) the russians created a new communist government that aligned with the central powers instead.