This chart has changed my students' argumentative writing! I use this a pre-writing/organizing tool for my students as they plan their responses to argument prompts.
This chart follows the "Toulmin method" of argumentation, so it's helpful for students to have familiarity with Toulmin-related terms before using the chart. (I always use the Toulmin Structure PowerPoint, listed on my products page, to pre-teach terminology before using this chart.)
I've used this chart successfully in all the grades I teach (9-12).