What is argument mapping and how can it help critical thinking?

Argument mapping is like having X-ray vision into your students' thinking.

Dave Kinkead Mar 9, 2020

There are a number of possible ways to teach critical and creative thinking in the classroom. One approach, very common in university undergraduate courses, is to teach critical thinking as a stand alone subject focusing on a range of concepts like psychology, informal logic, and argumentation.

Another approach, best realised in the Philosophy for Children movement, is to incorporate a small session (approximately an hour per week) of collaborative inquiry into the weekly class schedule. Alternatively, critical thinking can be integrated across the curriculum by making thinking an object of inquiry in all subjects, something we articulate in our Teaching for Thinking program.

Regardless of the approach however, there are a range of tools and techniques that can help students think about their thinking. And one such tool is argument mapping.

What is argument mapping exactly?

Argument mapping is the visual representation of the inferential structure in our reasoning. It's a way to show which claims justify what and how. Argument maps provide a useful focal point to, and scaffolding for, our reasoning processes.

The visual nature of argument mapping makes it a very effective way of analysing the reasoning process around specific inferences. It allows us to "cut through" the rhetoric skin of language and expose the underlining logical skeleton - something philosopher Tim van Gelder has described as "having x-ray goggles into students' minds".

An argument map

Argument mapping as a tool for improving our thinking has a pedigree that goes back over 100 years. Recently however, a number of studies have shown that argument mapping is one the most effective ways to improve students' cognitive skills ...

... the critical thinking gains measured [from 6 months of argument mapping] are close to that which could be expected to result from three years of undergraduate education.

-- Butchart et al (2009) p228

Why does argument mapping work?

One of the main reasons that argument mapping has proven so useful as a thinking aid is that it forces us to confront our reasoning processes. When we think to ourselves, we tend to think in associations.

Paris <==> France <==> Croissant <==> Yum!

These associations are multi-directional. The idea of France might lead us to thoughts about croissants, or Paris, or both. Paris in turn, might lead us to good wine, snooty waiters, and the Eiffel Tower.

But the inferential process of argumentation is not. Inferring is a uni-directional process where we move from premises to conclusion. The creative and divergent aspect of association is very different to the critical and convergent aspect of inference.

Then later, when we try to think out loud or on paper through language, we are constrained by the linear structure of narrative. We can start a story anywhere but one sentence must still come after another.

Narrative is linear but our reasoning is not.

Argument maps don’t have that constraint. Argument maps are tree-like structures called directed graphs which more accurately represent good reasoning. Importantly, argument maps show the direction of our inferences.

And this is where argument mapping really shines. A critical thinker will have strong justifications for their beliefs. In written narrative or even symbolic logic, it is not clear how individual propositions support specific claims. Argument mapping however, makes this explicit. As my colleague Peter Ellerton observes ... "It's all about the arrows!"

In this way, argument maps provide us with a scaffold to think about our thinking in a way that more accurately respects the norms of reason. They force us to move beyond the mere association of ideas and make our thinking the object of inquiry.