In "Learning the Language," the author sets up the story for audiences of different discourse communities: those in the medical field and those who are not. I think it's important for the author to understand the audience so that unneccessary help in de-coding the medical terminology is not used. If the audience was just for doctors and those familiar with medical jargon, they would be offended by someone in the discourse community over-simplifying. For this article, however, it was appropriate to include the mom, who broadened the audience of readers to include those unfamilar with the medical terms.