Trial and Tribulations of Exploring Earth
(Summary of a presentation by Glenn Kroeger on 1/10/04)
Audience
Students taking an introductory geoscience course include a very small number who are either intent on or investigating majoring in the discipline. This is due primarily to the absence of geosciences in most high school offerings. The vast majority of students are taking the course to fulfill general education science requirements while avoiding the physics and chemistry departments. Within this throng are a small number of “latent geoscientists.”
Introductory geoscience courses
In order to satisfy the diverse needs of this audience, geoscience departments typically offer several introductory courses. A common approach is to offer one or more courses with appealing topics such as “Environmental Geoscience” or “shake and bake” topics such as “Natural Hazards” or “Earthquakes and Volcanoes.” In addition to these topical courses, departments usually offer the standard survey course in geology “Physical Geology.” This course is usually offered with a laboratory.
A persistent problem with this dual track approach to introductory geoscience is that “latent geoscientists” often enter through the topical courses and miss the complete survey of the discipline and accompanying lab offered in the Physcial Geology course.
Physical Geology courses
The standard “Physical Geology” course emphasizes geologic processes and includes a study of minerals, rocks, interior geologic processes (plate tectonics, magmatism, structure of the Earth, etc.) and surface geologic processes (streams, glaciers, deserts, etc.). This course is often the first half of an introductory sequence with a second course in Earth History which covers specific events in the development of the Earth.
The laboratory accompanying Physical Geology traditionally includes hand specimen identification of minerals and rocks, work with geologic and topographic maps, and field trips.
The “cost” of introductory labs
Introductory laboratory courses are “expensive” for departments and institutions. Beyond facilities and supplies, there is a imbalance between student and faculty credit for lab work at most institutions. In a typical “semester hour” system, labs usually only deliver one semester hour of credit to the student, but count two to three times that much in a faculty members teaching load. In a 4-4 curriculum, lab courses usually offer no more student credit than non-lab courses but count 50% to 100% more toward a faculty members teaching load.
The reasons behind this inherent imbalance seem mysterious. Why not solve the problem by increasing the student credit for labs? Evaluating this “solution” leads to the conclusion that it would become very difficult and much more costly for science majors to complete their curricula which are full of lab courses.
Exploring Earth Format
The concept behind the Exploring Earth course at Trinity is to offer an introductory geoscience course that includes the experiential components of a traditional lab course with a lower “cost” than the traditional lecture-lab course. The course carries 3 credit hours for students and 3 contact hours for faculty. The course actually meets 4 hours per week, nominally 2 lecture and 2 lab/activity hours. All meetings are in the same facility so that hands-on activity can take place at any time. This is the “studio science” course model.
Exploring Earth Goals
Exploring Earth was designed with the follow goals:
Constraints
Exploring Earth had to be developed quickly since it would have to replace our existing introductory Physical Geology lab. The course needs to be structured so that any faculty member in the department can teach it.
Version 1
The first incarnation of Exploring Earth was based on a series of one-week project which followed the traditional sequence of a Physical Geology lab course: minerals, igneous rocks, sedimentary rocks, metamorphic rocks, geologic time, geologic cross-sections, geologic maps, topographic maps, earthquakes and plate tectonics. The topographic map work included work with volcanic features and groundwater. The projects were supplemented with two all-day field trips. The mineral labs were enhanced with a lab involving identification of minerals in common household cleaners using X-ray diffraction and the rock labs were enhanced with thin-section work using polarizing petrographic microscopes.
Problems with Version 1
There were only two problems with the first incarnation of Exploring Earth; students and faculty!
Although student evaluations of the new course were essentially identical to previous evaluations of the Physical Geology lab, they did not respond to the new format with the desired degree of self motivation and inquiry. This seems to result from the fact that the students didn’t have any content background in geosciences before the course, so they were neither interested in or capable of posing intelligent questions nor formulating reasonable approaches to answering questions.
Faculty found the new format to be frustratingly compressed. There seemed to be too little time for building content background and engaging in discussion with students. The rapid fire pace of weekly projects made for a constant battle to stay “on schedule.”
For three semesters, we tweaked the projects in Exploring Earth to fix some of the perceived problems. Project content changed and the total number of projects reduced to “decompress” the course schedule. These changes did result in some improvement, but the fundamental faculty discontent remained.
Last summer and fall, Dr. Kroeger tried a significant modification to the course structure. One week projects were grouped into larger integrated two-week projects. For example, the igneous rock project was grouped with the volcanic landform project. In generating these projects, there was an attempt to make the project goals larger and more aggressive. Geologic time and geologic cross-section projects were grouped and a major emphasis was placed on students learning to interpret rocks, cross-sections and maps together to deduce geologic sequences of events. While these changes brought some additional student and faculty satisfaction, they did not cure all of the perceived problems with the course.
Plans for Version 2.0
Plans are underway for a major revision to the course over the summer of 2004. The main goal of this revision is to address the problems of lack of necessary student curiosity and background. These plans include: