The premise of student-centered teaching is to respond to the ways in which students engage with the context and content of their learning, and therefore the purpose of this study was to find out how students visualize three-dimensional statics problems from two-dimensional diagrams early in a first-year engineering course. Think-alouds were conducted where students were asked to describe magnitudes and directions of various forces acting in three-dimensional spaces. Three key themes emerged: students have more trouble visualizing points behind, or vectors pointing into, the plane of the page; students may not use contextual clues to aid in their visualization; and students rely on equations to answer problems even when not necessary or even possible to do so. These findings are important to instructors in disciplines where spatial visualization is important because as they are already "experts" in this skill, they may underestimate the difficulty students initially face in approaching these problems. The value of using think-alouds to reveal student thinking as they struggle with concepts is also discussed.