Rate the strength of each logical link

Assign a confidence to each "supports" or "rebuts" link, not just to the conclusion.

Why it works

The strength of an argument is determined by its weakest link, not the average of all its links. Rating individual links makes the weakest link visible and directs both analysis and information-gathering toward it. This prevents the common mistake of treating an argument as strong because several reasons are plausible, while the one load-bearing link is the one that has not been examined.

How to do it

1. After drawing the map, go through each "supports" and "rebuts" link and rate its strength: strong, moderate, or weak.
2. Identify the weakest link in the argument — the one the conclusion most depends on.
3. Invest any additional research or analysis in that link specifically.
4. Revise your overall confidence in the conclusion based on the weakest link, not the average.

Evidence

Chain argument logic holds that the weakest link constrains the whole; this is a normative principle in formal logic. Rating individual steps is standard in structured analytic techniques used in intelligence analysis. (mechanistic)

Link strength ratings are subjective; the practice improves awareness of weak links but does not eliminate the subjectivity of the assessment.

Common mistake

Averaging link strengths mentally and concluding the argument is "pretty solid" overall, when in fact the conclusion follows only if one specific weak link holds — which it may not.