I have created a sort that has twelve short stories. Under each story, there is a place to label one of the 4 author's purposes that the Virginia SOLs 3.5a/3.6e ask of students: Inform, Entertain, Persuade, & Explain. There is also room for the student to explain why they have selected the author's purpose.
This also matches RL 3.2 common core: Recount stories, including fables, folktales, and myths from diverse cultures; determine the central message, lesson, or moral and explain how it is conveyed through key details in the text through the correlations
There is a second sheet with 4 headings of Inform, Entertain, Persuade, & Explain. This is used as a sorting mat prior to the students writing the author's purpose & identifying the reason why. This is a column graphic organizer. I let my students glue the 12 stories under the correct heading once we are done with the sort. They are displayed for a bit, but sent home for reinforcement.