September 2001 Journal of Geoscience EducationVolume 49, Number 4
Enhancing Students' Understanding of Risk and Geologic Hazards Using a Dartboard Model
Timothy Michael Lutz, Department of Geology and Astronomy, West Chester University, West Chester, PA
URL for this article: http://www.nagt.org/nagt/jge/abstracts/sep01.html#v49p339
X-Ray Diffraction Simulation using Laser Pointers and Printers
Neil E. Johnson, Department of Geology, Appalachian State University, Boone, NC
The conceptual leap from point array to diffraction patterns has long been recognized as challenging. For more than sixty years it has been known that an analogy can be drawn between optical and X-ray diffraction, requiring only a source of monochromatic light and an array of scatterers with spacings of 50 - 200 ???m. Inexpensive lasers fulfill the first requirement, but the second has been problematic due to difficulties in producing scattering arrays. A number of approaches have been used, including pantograph reduction, several types of photographic reduction, and even standard sieves, but all require significant preparation, limiting in-lab experimentation.
Laser printers with resolutions of 600 or 1200 dots per inch (one dot per 42 or 21 ???m) are inexpensive and readily available. Improvements in the screen magnification capabilities of common graphics software allow students to create and modify arrays, print them on transparencies, and illuminate them with laser pointers. Introductory examples can demonstrate basic principles, whereas advanced examples can illustrate plane lattices, stacking faults or even powder diffraction. The turnaround time from idea to observation is as little as a few minutes, allowing students to experiment with near real-time feedback.
URL for this article: http://www.nagt.org/nagt/jge/abstracts/sep01.html#v49p346
The Problem of Sample Contamination in a Fluvial Geochemistry Research Experience for Undergraduates
Charles B. Andersen, Department of Earth and Environmental Sciences, Furman University, Greenville, SC
Geochemical analyses are difficult because all samples have an unknown composition. As most geoscience programs do not teach "techniques" courses, teaching analytical technique and critical data analysis becomes a priority during the undergraduate research experience. The analysis of rivers is an excellent way to teach geochemical techniques because of the relative ease of sample collection and speed of sample analysis. The sample collection and processing steps, however, are subject to a variety of mistakes that affect sample integrity.
This paper focuses on the potential sources of sample contamination during the sampling, filtering, and bottle cleaning processes, and reviews methods to reduce and detect contamination. Training at the beginning of a research program is helpful, but during a ten-week or shorter summer research experience, training time is of necessity short and much learning occurs in the actual research environment. An emphasis on contamination sources and the one million times dilution approach to cleaning will help avoid sample contamination. The cleaning process, though a critical analytical technique, is a tedious, dull, and seemingly menial task. As a result, faculty members engaged in undergraduate research experiences face a difficult task when teaching the need for cleanliness in the laboratory and field. The participating students, however, learn an important lesson of the need for "mindfulness" in the research process.
URL for this article: http://www.nagt.org/nagt/jge/abstracts/sep01.html#v49p351
Urban Field Geology for K-8 Teachers
William F. Kean, Department of Geosciences, University of Wisconsin-Milwaukee, Milwaukee, WI
Larry G. Enochs, Department of Science and Mathematics Education, Oregon State University, Corvallis, OR
Geologists have long appreciated the value of field trips. Likewise, the National Science Education Standards recommend them for K-8 science curriculum. Yet, few teachers avail themselves of quality field opportunities close to home. We presented summer institutes for urban teachers in Milwaukee that centered on several Lake Michigan beaches within the bounds of their school district. Field and laboratory activities were developed in the context of the geology of southeastern Wisconsin. As an example activity, we compared the sand from four different beaches for grain size, magnetite content, as well as fossil and modern Zebra Mussel shells. The different beaches show different characteristics that were related to their location and origin. We encouraged the good field trip teaching practices of "Teaming-Up," reducing novelty space, and pre- and post-field trip activities. The teachers shared lesson plans and developed action plans for implementing the changes in their curriculum.
We determined that the teachers in these three-week workshops increased their personal belief in their ability to teach earth science more effectively. They felt more comfortable with content material and found that action plans were an effective way to enact change regarding field trips in their curriculum and in their schools.
URL for this article: http://www.nagt.org/nagt/jge/abstracts/sep01.html#v49p358
Teaching Race, Class, and Cultural Issues in Earth Sciences to Enhance Multicultural Education
David A. Padgett, Department of Geography, Tennessee State University, Nashville, TN
URL for this article: http://www.nagt.org/nagt/jge/abstracts/sep01.html#v49p364
Learning Activities for an Undergraduate Mineralogy/Petrology Course - "I AM / WE ARE"
Philip C. Goodell, Department of Geological Sciences, University of Texas at El Paso, El Paso, TX
Traditional undergraduate curriculum in the geological sciences consists of mineralogy, optical mineralogy, and petrology. In an attempt to better serve student needs, changes to this classical approach are being made at many educational institutions. A new entry-level mineralogy/igneous petrology course has been initiated, and the present report illustrates a series of learning activities that are a part of this course.
A concise flow of ideas from chemical elements to minerals to rocks is emphasized, and magmatic evolution as promoted by Bowen's Reaction Series is the pedagogical methodology. Individual learning activities alternate sensibly with cooperative ones. Data sources include textbooks, the library, journal articles, and the Web. Data becomes increasingly complex, and must be analyzed and integrated for individual and group presentations. The concise, focused, and related series of ideas and data appear to provide more effective and efficient learning. Student response to the self-identify of the I AM activities is very positive.
URL for this article: http://www.nagt.org/nagt/jge/abstracts/sep01.html#v49p370
Column - Computational Geology 17: The Total Differential and Error Propagation
Len Vacher, University of South Florida
Column - Research Methodologies in Science Education: Assessing Students Alternative Conceptions
Julie C. Libarkin, Science Education Department, Harvard-Smithsonian Center for Astrophysics)
Josepha P. Kurdziel, Department of Ecology and Evolutionary Biology, University of Michigan