Claims and Evidence: Reading
What to master
A claim is an assertion that needs support; evidence is what backs it. Distinguish claim types: factual (verifiable), causal (X produces Y), evaluative (X is good/bad), and policy (we should do X). Each demands different support. Evaluate whether evidence is relevant (bears on the claim), sufficient (enough to generalize), and credible (reliable source, appropriate method).
Watch for the warrant-the unstated assumption linking evidence to claim. "Test scores rose after we added recess; therefore recess improves learning" hides a warrant that no other factor changed.
Traps
- Anecdote as proof: one story cannot establish a general trend.
- Correlation/causation confusion.
- Appeal to authority where the expert is outside their field.
- Selective evidence or a statistic stripped of its base rate.
- Confusing evidence (data, example, testimony) with interpretation of it.
Worked example / rule of thumb
Claim: "Remote work reduces productivity." Evidence: "A survey of twelve employees at one firm reported lower output." Problems: tiny, non-representative sample; self-report; single firm. The claim outruns the evidence.
Rule of thumb: for any argument, ask three questions-What exactly is claimed? What supports it? What must be true for that support to count? If the third answer is unstated, you have found the warrant and a likely question target.