One of the best ways to demonstrate why a given piece of evidence supports the thesis, claim or position of an argument is to explain the reasoning process by which they are logically connected. In the Toulmin method, these explanations are referred to as warrants.
First, for each claim that is debatable, or open to question, a reason is offered that supports the claim's validity. A warrant-consisting of a sentence or two-then follows, explaining the reason. Finally, evidence is supplied that supports connecting the reason to a given point or the overall claim of the paper.