Students will make stronger arguments when they grasp the distinction between an explanation (reason why something is true) versus a justification (reason to believe that something is true).
This distinction is especially helpful when teaching students to use evidence to support a claim (i.e., justification), vs. merely summarizing plot, explaining why something happened, or giving a list of historical events. While arguments do sometimes include explanations, they are primarily concerned with justification. Therefore, we rarely include explanations in an argument map.
If you’re not sure whether to include a statement in your argument map, just ask the Reason Rule question: Does it give a reason to believe the claim above? If so, it’s a premise that you should include in your map; if not, then you shouldn’t map it underneath the other claim.
Keep the distinction between explanation and justification in mind as you try the following exercises.