It's not always easy to explain to students the concept of text structure. Students focus on the content of the story as they read and work to comprehend a book or passage. Noticing the structure of a story, requires stepping back and actually noticing how a story was put together. This requires critical thinking skills that for an untrained eye can be complicated! There are other skills, as well, such as noticing the author's purpose for writing or point-of-view which require similar thinking.
I've started using a chart to explain this to students which asks them to think about the differences between reading skills that are used for what happens INSIDE a story versus skills that happen OUTSIDE a story. One requires looking into the story itself...while the other requires this step back to consider what the author had in mind. With the students I actually write the skills inside the open book that are INSIDE the story questions, such as: characters, plot, setting, inferencing, and other "right-there" type questions. Around the outside of the open book we write the question types that we would find OUTSIDE the story by thinking about how the writer had in mind when they WROTE the piece.
This type of introduction can then launch a teacher into the deeper teaching of TEXT STRUCTURE and other OUTSIDE the story skills. Try it! I'll be using it with 4th graders tomorrow.
Hang in there! Summer's coming!