Separate the claim from its reasons

Start every map by writing the central claim and the distinct reasons offered for it.

Why it works

In natural language, claims and reasons are woven together in ways that make the logical structure hard to see. Separating them forces precision: a "reason" must be a statement that would, if true, provide support for the claim. This distinction also reveals when what sounds like a reason is actually a restatement of the claim in different words — circular reasoning is invisible in prose but immediately visible on a map.

How to do it

1. Write the main claim — the conclusion to be evaluated — in a box at the top or center.
2. For each supporting point, ask: "If this were true, would it give me reason to believe the claim?" Only put it on the map if yes.
3. Draw a line from reason to claim, labeled "supports."
4. Check whether any "reason" is just the claim rephrased — if so, remove it.

Evidence

Argument mapping studies found that making claim-reason structure explicit improved students’ ability to identify flaws in arguments and to construct better ones. Van Gelder’s controlled study of the Reason! software showed significant reasoning gains over a semester. (observational)

Studies are small-scale and conducted in educational settings; transfer to professional contexts is plausible but less directly measured.

Sources

• van Gelder, Bissett & Cumming (2004), "Cultivating Expertise in Informal Reasoning," Canadian Journal of Experimental Psychology

Common mistake

Listing considerations rather than reasons — a list of "relevant factors" is not an argument map. Each item must be linked by a logical relationship (supports, rebuts) to the central claim.