In our last post we provided an analysis of Dewey’s definition of “critical thinking.” Generally, critical thinking is the process by which one defines a problem and then formulates and evaluates possible solutions to that problem. An essential addition that we made to Dewey’s definition is the requirement that students open their minds to other perspectives and experiences when collecting potential solutions so that they can more readily find the most effective solution to the given problem.
Critical thinking is an essential skill for all academic disciplines, whether it be the humanities and social sciences, or math and science. Thus, educators in every discipline should be concerned about how exactly they can best develop critical thinking skills within their classrooms. In our first article in the series on critical thinking we worked to define, in a concrete way, what the skill of critical thinking entailed. In this article, I will argue that one of the most effective strategies to encourage critical thinking amongst students (8th through 12th grade) is to help them become familiar with the process of argument mapping. Generally, the reason why argument mapping, as a pedagogical tool, increases critical thinking skills amongst students is that it involves students actively constructing and evaluating prose-style arguments in a visual way.
First, it would be helpful to outline exactly what argument mapping is. Mapping is the process of creating a visual representation of a logically structured argument. The map visually recreates the structure that is normally hidden within a prose argument. The main claim goes at the top, and boxes containing the premises go underneath, with arrows connecting the boxes to indicate the inferential relationships between claims.
Consider the following example of a prose style argument:
It is raining outside: I walked outside my front door this morning and I immediately got soaked by the rain. Every time it rains puddles form everywhere on the ground. Therefore, there must be puddles everywhere outside.
A simple argument map, which can construct this argument in a visual way may look like the following:

Notice that the argument map looks like an upside down tree. The main claim, “There must be puddles everywhere outside” is positioned at the top of the map. The premises…