Results from the Volcanic Concept Survey (VCS) indicated that many undergraduates do not fully understand volcanic
systems and plate tectonics. During the 2006 academic year, a ten-item conceptual survey was distributed to
undergraduate students enrolled in Earth science courses at five U.S. colleges and universities. A trained team of graders
scored 672 completed surveys, coding responses to each item with a score, out of 3, based on accuracy and
comprehensiveness. Questions requiring only basic content knowledge (e.g., terminology, volcano topology) received
more high scoring responses than questions requiring higher thinking and deeper conceptual connections (association
with plate tectonics, prediction of hazards and impacts on the environment). The mechanics of eruptions also appeared
to be poorly understood. Special attention was paid to students’ alternate conceptions about where volcanoes are likely
to form. Male students, students highly interested in science, and students who lived in a volcanically active area
received significantly higher total scores than other student groups. Science, technology, engineering, and mathematics
(STEM) majors also performed significantly better than non-STEM majors. Understanding the nature of student
comprehension and misconception may be useful for geoscience educators seeking to address student preconceptions
and promote conceptual change.