There are various questions readers can pose to help them practice understanding an author's purpose in a passage of writing, such as why they author wrote the passage and what kind of rhetorical structure he used, what the author wanted to make the reader feel and how to connect passages to the reader's own writing in which he may have a certain purpose. Readers should also note how purpose may change from passage to passage in a text.
Acquiring a greater understanding of why a writer may have included a specific passage in a text goes a long way to perceiving the author's purpose. Student readers can be provided a list of reasons of why writers compose pieces and they can choose specific reasons to assign to a passage. The structure of a passage, whether it is expressing an opinion, providing background to a case or listing facts, also offers significant clues to an author's purpose.
Many times part of the author's purpose can be revealed in the emotions that the passage causes the reader to feel. After reading a passage, a reader should ask himself how he feels differently about the subject than before he read the passage and deduce some of the author's purpose from this. Some questions of purpose can also be answered by evaluating the reader's purpose when he is writing a similar piece.