Comparative thinking is one of our first and most natural forms of thought. When we are infants, one of the first differences we must identify is that between mother and other. Without the ability to make comparisons—to set one object or idea against another and take note of similarities and differences—much of what we call learning would quite literally be impossible.

You may be wondering why we want to look so closely at comparative thinking. What makes it so special? The answer lies in the research of renowned educators Robert Marzano, Debra Pickering, and Jane Pollock (2001). By compiling the available research on effective instruction, Marzano, Pickering, and Pollock found that strategies that engage students in comparative thinking had the greatest effect on student achievement, leading to an average percentile gain of 45 points (p. 7f). More recently, Marzano's research in The Art and Science of Teaching (2007) reconfirmed that asking students to identify similarities and differences through comparative analysis leads to eye-opening gains in student achievement.

What Can Compare & Contrast Do for Students?

Strengthen Students' Memories

By focusing student thinking on analyzing pairs of ideas, the Compare & Contrast strategy strengthens students' ability to remember key content.

Develop Higher-Order Thinking Skills

Compare & Contrast acts as a practical and easy-to-use introduction to higher-order thinking.

Increase Student Comprehension

Compare & Contrast improves comprehension by highlighting important details, making abstract ideas more concrete, and reducing the confusion between related concepts (think meiosis versus mitosis).

Enhance Students' Writing in the Content Areas

The Compare & Contrast strategy strengthens students' writing skills by providing a simple structure that helps them organize information and develop their ideas with greater clarity and precision.

Develop Students' Habits of Mind

In their years of research into the defining characteristics of intelligent behavior and thought, Art Costa and Bena Kallick (2008, 2009) have identified 16 “habits of mind.” By nourishing these habits in our students, we give them the tools they need to use their minds well, thus increasing their chance for future success. Using Compare & Contrast in the classroom will help students develop these habits of mind: thinking flexibly; thinking about thinking (metacognition); striving for accuracy; applying past knowledge to new situations; and thinking and communicating with clarity and precision.