Background
A secondary school in suburban Melbourne was seeking evidence-based approaches to critical thinking education. Standard essay instruction produced writing that was often structurally sound but logically shallow — students could organise paragraphs but struggled to identify and evaluate the premises underlying their own claims.
The Intervention
Working with the school's English and Humanities faculty, we designed a six-week curriculum module integrating argument mapping into existing units on persuasive writing and contemporary issues.
The module proceeded in three phases:
Phase 1: Reading Arguments (Weeks 1–2)
Students used argument mapping software to map the structure of provided texts — opinion pieces, policy briefs, and speeches. The goal was to identify conclusions, premises, evidence, and objections.
Phase 2: Constructing Arguments (Weeks 3–4)
Students built argument maps for their own positions on assigned topics before writing their essays. They were required to identify at least three premises and anticipate at least two objections.
Phase 3: Critiquing Arguments (Weeks 5–6)
Pairs of students exchanged maps and essays, providing structured feedback identifying weak premises and missing evidence. A whole-class session concluded each week with discussion of the most generative critiques.
Results
Comparing essays written before and after the module, assessors (blind to condition) rated post-module essays significantly higher on:
- Logical coherence: The degree to which conclusions followed from premises.
- Premise quality: The strength and specificity of supporting reasons.
- Counterargument engagement: Whether the essay acknowledged and responded to objections.
Student surveys showed substantial increases in confidence in identifying logical fallacies and in structuring their own arguments.
Limitations
The trial was not randomised, limiting causal inference. Teacher enthusiasm for the approach may have contributed to outcomes through expectation effects.
Next Steps
A randomised controlled trial across six schools is planned for the following academic year.