RAPID AND AUTHENTIC ASSESSMENT OF STUDENT UNDERSTANDING USING CONCEPT SKETCHES

Authentic assessment is difficult in introductory geology courses, especially those with more than a hundred students. We have found that using concept sketches as an assessment tool is much faster than grading essays or other constructed-response questions and is more authentic. Concept sketches are annotated sketches, in this case created by the student, that are labeled with processes and relationships, in addition to names of geologic features. They are incredibly useful for teaching, to assign as student homework, and for exams. A typical concept-sketch question for igneous processes would ask the student to sketch a convergent margin, describing in complete sentences on the sketch where and how magma is generated, what type of magma is produced, what styles of volcanic eruptions are common for such magmas, and what type of volcanoes result. To answer such a question, a student cannot have memorized isolated facts. Instead, the student must have a coherent understanding of a geologic concept or system, and must be able to represent the concept with all its interrelated processes, geologic features, rock types, and other aspects. This type of coherent, sketch-centered understanding is authentic, in that it is consistent with our learning objectives and with how geologists represent, think about, and discuss geologic concepts. We have extensively implemented concept sketches in structural geology classes with ~25 students and in introductory geology courses with 230 students per class. Our experience from these classes is that grading a concept-sketch question typically requires 10 to 45 seconds (really bad ones take longer), permitting a hundred such questions to be graded in less than an hour. Concept-sketch questions can be conceived for most subjects in an introductory geology course, especially plate tectonics, deformation, relative dating, volcanoes, rivers, and groundwater. Using concept sketches has revolutionized our own teaching, including how we conduct classes, assign homework, assess student learning, and recommend to students how they should study, self assess, and learn.