Next, you'll need to read each of the sources critically while thinking about these questions: What is the credibility of the source? Is there any noticeable bias? How does the author form his or her argument? What are the important themes, main ideas, and arguments presented in the document? Next, you'll need to read each of the sources critically while thinking about these questions: What is the credibility of the source? Is there any noticeable bias? How does the author form his or her argument? What are the important themes, main ideas, and arguments presented in the document?