This lesson is specifically geared towards STAAR Writing only. There's a 5th bullet in the rubric that breaks down the different styles of writing. Ideally, a teacher would teach the 3 expository and 4 persuasive and the students choose their favorite method for the task at hand.
When reading the released essays from TEA, you will see the descriptions explain objective 5. If this doesn't make any sense, just let your kids have fun and use this a prewriting worksheet.