Stephen Toulmin developed his model based on his study of the way lawyers argue cases in court.
Claim
What is the writer's thesis, charge, or central assertion?
Another way to consider this is to ask, what conclusion(s) does the writer want
the reader to come to after considering all of the evidence?
Data
What evidence does the writer present in support of the claim?
Does the writer appeal to facts, statistics, and logical reasoning?
Does the writer appeal to the readers' beliefs, values, and/or needs ?
Does the writer present the testimony of experts on the subject? How
reliable are this writer's sources?
Warrant
What connection is there between the data and the claim?
Does the writer base the argument on any assumptions that the reader must accept
for the argument to proceed?
For example, in the Declaration of Independence, the colonists claim that the "United States are, and of right ought to be, free and independent...." They base their argument on the belief that the right to govern comes from the people. This is the warrant of their argument. If the reader does not accept this assumption or warrant, but instead believes in the divine right of kings (the right to govern comes from God who grants power to the King), then the colonists have no grounds on which to declare their freedom.
Backing
Does the writer present any evidence to back the warrant?
If so, what kind of evidence is presented?
Rebuttal
Does the writer present any counterarguments to the claim?
Does the writer describe any situations where the claim may not be true?
If so, how does the writer refute these counterarguments?
Qualifier
Does the writer modify the strength or certainty of the claim with words like usually,
generally, sometimes, often, or except?