USING GEOLOGICAL CONCEPT SURVEYS TO GAUGE THE RELATIVE EFFECTIVENESS OF COURSE COMPONENTS AND INSTRUCTIONAL METHODS IN GEOSCIENCE CLASSES

Recently the University of Minnesota's Introductory Geology Program began to develop geologic concept surveys to gauge changes in pre-instruction and post-instruction student knowledge. Each survey consists of roughly 20 questions on various geologic concepts, but for each question students are also asked to indicate their confidence in their answer. So changes in both student accuracy and confidence levels can be tracked through the course of the semester. Although originally intended to quantify the effectiveness of an ongoing lab curriculum revision, due to the introductory program's sheer size and internal design these surveys also provide a rich data suite on the relative effectiveness of different course components and methods of instruction.

Survey questions were chosen to cover three content subsets, topics only covered in lecture, topics only covered in lab and topics that were covered in both lecture and lab. In addition, whenever possible, survey questions were designed to integrate known misconceptions and alternate conceptions students have about how the Earth works. Results from the study were striking. As expected, labs proved to be far more effective than lecture, but the degree to which traditional lectures failed to alter students' concepts was dismaying. On most lecture-only topics, significant changes in student knowledge only occurred when lecture activities were designed to specifically address and challenge students' prior understanding of the topic. For the most part these 'interventions' were capable of raising the lecture component's effectiveness to rival the lab component's, but few instructors are aware of the necessity for these interventions.

In order to design an effective lecture 'intervention', instructors also need to know their students prior understanding of the topic or the background students will use to approach the topic. Without this information, classroom instruction, curriculum development and concept inventory construction will not be effective. Unfortunately, even the briefest investigation reveals how little we really know of our students' perceptions of the Earth.