The term design thinking has recently gained prominence within postsecondary design programs across the United States. The term is often used to explain and advocate for design's unique approach to solving problems in innovative ways. The term is also used as a general description for unexplained or ill-defined representations of what designers do. If design educators have a clear understanding of design thinking, they can improve teaching and learning, and reframe design-based and interdisciplinary inquiry. This article addresses design thinking through two layers. The first layer highlights key ways that designers think through an overview of more than 50 years of design thinking's foundational literature. The second layer reports a 3-year-long, teaching-and-learning research project that compared learning in a design course and a similar nondesign course. The research project explores the application of design thinking's key ideas through the two courses. The project examined learning by 110 students enrolled in two courses during an annual, residential, summer enrichment program for high school seniors. The courses were structured in parallel ways for exploring design thinking and wicked problems, but addressed design and nondesign topics. Qualitative and quantitative analysis of the courses and student learning demonstrate how the students used attributes of design thinking. The results challenge design educators to reconsider how design thinking may influence the classroom and inquiry.In recent years, the term design thinking has gained prominence within postsecondary design programs across the United States. Design thinking, as a process, can be a valuable approach and descriptor for what designers do. Design educators use the term to explain and advocate for the potential that design has to improve lives, solve problems, and enrich interdisciplinary collaborations. But, do we know what design thinking is? As design educators and scholars, we teach our students how to design and what design's effect can be in improving quality of life. We have an obligation to continually improve our teaching. Improving our teaching requires refining our understanding of how we design. If we consider carefully the more than half-century of focused research on design thinking, we will gain a stronger understanding of what we do-and how design thinking can transform our actions, enhance our teaching, and provide ways for us to reshape design's position within the academy.How designers think about a solution may seem opaque or foreign. At the same time, design thinking may be inherent in the ways that our students and colleagues already understand and act on ideas. To advance our use of design thinking, two layers of design knowledge must be addressed. The first layer requires that we (as design educators and designers teaching) understand how designers recognize, think through, and solve the problems they face. The second layer requires exploring how far design thinking extends. Do students learn the design thinking ...