Mickey Eugene Gunter
Department of Geology and Geological Engineering
University of Idaho
Moscow, Idaho 83843
ABSTRACT
Teaching large science classes (200 or more students) to non-science majors is a tremendous challenge to the university professor. There are countless difficulties in both logistics and determining content. After teaching such a beginning geology class for three years, I have developed a course structure that seems to solve many of the common problems. A departure from the straight 50-minute lecture format is critical. I have integrated in the lecture short movies, slides, computer demonstrations, a video-microscope system, an 8 mm camcorder, digital photography, many demonstrations of geological phenomena, and several "real-life" stories relating geological events to everyday life. In this article I discuss these and other techniques which depart from the normal, accepted style of teaching, while still providing a sound background in science and geology to the non-science university student.
Key words: Education - audio visual; education - computer assisted instruction; geology - teaching and curriculum
Introduction
When I was a Ph.D. student, I thought I would never want to teach introductory geology classes. After all, that is the course given to the instructor who could not do anything else - the "Rocks for Jocks course"; at least that is the perception of many students and, unfortunately, faculty and administrators. Possibly, some of this reputation is earned. The university structure does not reward quality teaching of these usually large courses (Stenstrom, 1991), and anyone attempting to excel in teaching these classes usually has little time for anything else. After three years of teaching beginning geology, my attitude has changed completely! Introductory science classes, like beginning geology, are predominantly composed of non-science majors. These courses provide a great opportunity to tackle scientific illiteracy so prevalent in our society today.
I teach approximately 400 students in the fall semester in two sections which meet for 50 minutes three times a week, and I have developed some methods which work for me and might be of general interest. I give some specific examples in this paper, but many of these could be modified and applied to other disciplines.
This paper is divided into six sections, the first discussing my philosophy, which determines my priorities and personal style of teaching. Then I present several in-class demonstrations I developed and real-life examples I use to show the students the relevance of geology, science, and critical thinking. I describe how we take 400 students on a field trip, one of the most important aspects of the course, and discuss the integration of the above into the course while still finding time to lecture. In the last section I give some examples of test questions that can be used in the large classes where tests must be graded by a computer.
Some of the demonstrations and stories may seem very childish; during my first semester of teaching I was reluctant to use some of them. After reading my evaluations however, I learned the students thought my demonstrations and stories helped them understand and remember concepts I presented. That semester, and the subsequent two, I received only positive comments from the students on the demonstrations and examples and suggestions to develop more.
This article may provoke considerable disagreement among college faculty, especially those who teach the beginning geology classes. It is not intended to criticize anyone or anyone's teaching style; it just describes my teaching methods and style with the hope that others may discover techniques that are beneficial in their classrooms.
Teaching Philosophy
My first lecture of the semester overviews my thoughts on the course and education in general, as well as what will be covered in the class. Policies on attendance, cheating, talking, and sleeping are covered, but are best summarized by a quote from a former professor of mine, "Education is the only product in America for which people will accept less than their money's worth." Thus, the responsibly is placed on the student; to check and require attendance in college is a waste of precious class time. If the students want to sleep in class, that's fine; they can do anything they want as long as it does not disturb the other "paying customers." This leads to another important philosophy: faculty time is better spent on the positives of the class than on the negatives. Our time is better spent helping students, thinking of innovative methods to take to the classroom, etc., instead of worrying about cheating, making multiple-colored test forms, checking attendance, etc.
I stress concepts and processes more than details and vocabulary. There are so many nouns in the sciences; the entire class could be spent defining them and making the students memorize them, but little good comes from this exercise. Of course, the students need some vocabulary, but I scrutinize every word I define.
I developed my philosophy during the first semester I taught beginning geology (spring 1990). I was reassured to read Palmer's (1991) article, "What should my neighbor know about the geosciences," because I felt I was addressing the points he made.
In-class demonstrations
Development and implementation of in-class demonstrations inspired me to depart from "normal" teaching methods in the large class of non-science majors; the students seemed to connect with these demonstrations The demonstrations take advantage of the fact most people are visual learners. They are not a substitute for lecturing, though, just a reinforcement. The demonstrations are listed below in the same sequence they are used in class.
I often use the overhead as a projection device for my demonstrations, as does Stadum (1992). In her paper, she lists eight examples she developed which can be used in large lecture rooms.
Computer demonstrations: An earlier paper (Gunter, 1991) describes the use of computer demonstrations in class. A computer is taken to class and attached to an LCD projection panel placed on an overhead. Even in a large lecture hall, the demonstrations can be seen. Interactive graphical programs work especially well, and, with the advent of multimedia and laptop computers, computer demonstrations are much easier to do and can convey more information. For suggestions about computer demonstrations, see Gunter (1991).
Tetrahedral polymerization: I have seen several demonstrations attempting to show how silica tetrahedrons join to form single chains, double chains, etc. Many of these examples do not work well in a large lecture hall because the objects used are too small. A tetrahedral arrangement can be made from four balloons. First, inflate four balloons. Then make 2 pairs by tying the ends together. Wrap the two pairs together to form a single tetrahedron. A small ball (e.g., ping-pong ball) can be stuck into the middle of the four balloons. This makes a nice, easily seen representation of a silicate tetrahedron. After some discussion about how (SiO4)-4 has a negative charge and attempts to change this charge to zero, another balloon tetrahedron can be introduced. One of the balloons on the new tetrahedron can be broken (which wakes up a few of the sleepers) and the two tetrahedrons combined to form a (Si2O7)-6 molecule. Then, the polymerization can be continued with the overhead. Single-chains, double-chains, and sheets of cork-ball tetrahedrons can be placed directly on the overhead, and the students can see the projected shadow.
Cleavage and fracture: Both of these phenomena deal with material rupture. Before they are discussed, stress and strain are defined and demonstrated. Then elastic and plastic are defined. To demonstrate elastic deformation, a rubber band can be placed around the wrist, stressed (i.e., stretched) and then released to snap back and cause a low level of pain to the professor. Silly putty can be used to demonstrate plastic deformation and the two types of plastic deformation - shape change without and with rupture. The silly putty is quickly pulled apart and breaks and is then slowly pulled apart, resulting in a shape change. (Stress, strain, and deformation are introduced here and the same demonstration used later to show how rocks behave under stress and how they behave differently depending upon the strain rate - i.e., whether they fracture or fold.)
To describe mineral cleavage, use a ball and spoke model, a crystal structure drawing, and a large sample (a foot square and an inch thick) of muscovite. Use a pocket knife to split the mica, and then rip it apart. By referring to the structure drawing and the structure model, the students can see the weak (001) plane. Then I use one of my favorite mineralogical quotes, "The physical properties of a mineral are directly related to its crystal structure."
To demonstrate fracture, select a mineral like quartz. The model and structure for quartz show no planes of weakness. Use a hammer to smash a piece of quartz and then place the broken pieces on the overhead and explain that fractures occur in minerals without planes of weakness and that fracture is the description of the broken surface.
This process can be repeated for as many minerals as you have (given models, drawings, and large mineral samples). I use the two above and an amphibole. Also, models and drawings of graphite and diamond are used in this discussion to show how another physical property, hardness, is directly related to these C-compounds crystal structures.
Crystal structure drawings are now easily made on personal computers with such software packages as ATOMS (for the PC or Macintosh, Eric Dowty, 521 Hidden Valley Road, Kingsport, TN 37663). Ball and spoke crystal models can be purchased directly from Klinger Education Products Corp. (112-19 14 th Road, College Point, NY 11356) or can be custom made (Gunter and Downs, 1991).
Introduction to rocks (hand samples & thin sections): This demonstration requires at least three people to carry all the equipment to class. It requires a video-microscope to view thin sections of rocks, a TV camera to view hand samples of rocks (I use an 8 mm camcorder), and a projection device for these video systems that produces at least a 10-foot diagonal image. The projection system we use has three internal LCD panels (green, red, blue) and is much smaller than a three-gun camera used for large screen TVs. This device also has two video inputs and a remote control to switch them, so the 8 mm camcorder and microscope camera can be hooked in simultaneously and switched from the stage. New technology has produced higher quality and smaller projection systems that are less expensive and more portable while producing larger and higher quality output. I also use a hand-held, battery-powered laser pointer for this demonstration (and any time I show slides). The laser pointer is worth the extra expense because it works so much better than any other pointer.
The demonstration also uses the overhead projector, a thin piece of mica, and two 6-inch square polarizers to simulate how a microscope works. For the rocks I use granite, basalt, folded gneiss, a well rounded, well sorted quartz sandstone, and a fossiliferous limestone. There are also matching thin sections for each.
After briefly defining the three rocks types and how and where they form, I place a one-foot thick folded gneiss on the overhead. I identify the fold and comment that although we cannot see through the rock now, if it is cut thinly enough, light can shine through and we can identify minerals and rock types with the microscope. Next, I place the polaroid sheets on the overhead, discuss their use in sunglasses, and place them crossed on the overhead to show how they block all the light. Then, the highlight of this demonstration, and quite possibly of the entire semester, occurs when I insert the thin muscovite flake at 45deg. from extinction between the cross-polars and all of the beautiful interference colors form a 10-foot image on the screen. To continue, I place a thin section on the overhead and explain its manufacture. Next, I place it between the cross polars and a few small specs of color can be seen. I then explain that the microscope is basically like the overhead with the polarizers except it magnifies the image. I then place the same thin section on the microscope stage and it appears 10 foot across on the screen.
I show and discuss each hand specimen/thin section pair. First, I place the hand specimen under the tripod mounted 8 mm camera. The new camcorders have macro lens, so you can get as close as you like. I try to show the characteristics of the rock that are visible to the students in lab. After viewing and discussing the hand specimen, I show its associated thin section with the video-microscope system. With my system, the two video input projector, it is very easy to switch from the camcorder image to the microscope image. The thin section views of the rocks can be used to show interlocking grains in the igneous rocks, rounded non-interlocking grains in the sedimentary rocks, etc. This overview before going into the details of petrography and petrology seems to help the students gain the big picture of rock types.
Chemical and physical weathering: After defining and discussing both chemical and physical weathering, I perform a simple demonstration which requires a calcite rhomb, HCl, a beaker, a knife, and the overhead projector. Scratch the calcite with the knife (mechanical weathering), and put the powder into the beaker, which is on the overhead projector. This is also a good time to review hardness. Next, pour some HCl into the beaker; the calcite powder starts to dissolve (chemical weathering). The bubbles of CO2 can be seen projected on the screen. This experiment also shows how chemical and physical weathering integrate in the breakdown of rocks.
Relative time: The concept of relative time is based upon such geological principals as superposition, original horizontally, unconformaties, and cross-cutting relationships. It requires the students to think in terms of 3-D and time and is one of the most important aspects in the understanding of geology. I use two demonstrations. The first is done with a computer and a graphics program (Gunter, 1991). The second moves from high-tech to very low-tech and uses four introductory geology textbooks. On the edge of the pages I indicate a different rock symbol on each book (e.g., sandstone for book 1, coal for book 2, limestone for book 3, and siltstone for book 4). I place book 1 on a table and discuss original horizontally. I place book 2 on top of book 1 and discuss the law of superposition. Next, I add book 3 and discuss further original horizontally and superposition. Before class, one side of this pile of books was partially painted blaze orange to simulate an intrusion; that side is now revealed by rotating the books, showing how an intrusion occurred after the sediments where deposited. Finally, an unconformity is created by removing book 3 and adding book 4. This demonstration, coupled with the computer demonstration, helps the students comprehend relative time.
Strike and dip: This concept is one of the most difficult for students to grasp, and any demonstration of it is helpful. My demonstration requires a foot square, 1/4 inch thick sheet of clear plexiglass, a squirt bottle of colored water, and a sponge. The plexiglass is placed flat on the overhead to represent a bed of rock. Next, it is tilted 10-20deg. and the strike direction defined and added with an overhead pen. Then, a few drops of water are squirted onto the plexiglass, with their flow direction defining dip. The sponge is used to clean the overhead.
Moon rocks and lunar geology: I devote a full class period to lunar geology and the moon rocks and use the same combination of equipment I used to introduce rocks (the video-microscope, camcorder, and projection system). The "Lunar petrographic thin section set" (obtained from Lunar Sample Curator, SN2, NASA LBJ Space Center, Houston, TX 77058) contains thin sections, rock chips, and soils from the moon. The rock and soil samples are imbedded in a clear epoxy disk. After lecturing for about 30 minutes on lunar geology, I show the lunar samples. I use the camcorder, in macro mode to show the small rock chips in the epoxy disk. The camera has enough magnification to display individual grains in the basalts and anorthosites in the rock chips. The white anorthosite and black basalt make it easy to explain which parts of the moon are white and black.
After looking at a rock chip, we view its associated thin section with the microscope. It is easy to see from the thin sections that they appear very much like earth rocks, the major difference being the lack of weathering due to the lack of water. The lecture on lunar geology, combined with seeing the moon rocks, is really appreciated by the students. This is a lecture that takes a considerable amount of work but is worth the time and effort.
It is absolutely critical to practice the demonstrations before they are done in class, almost to the point of having them completely memorized. In addition, I present more than one example of a concept. I believe it is better to teach fewer things well than to teach more things poorly.
Several pieces of hardware are used in the above demonstrations. The overhead projector is used frequently and provides an easy, inexpensive tool for showing small objects to large classes. Also, 35 mm slides can be scanned into a computer and made into overheads, eliminating the need to set up both a slide and overhead projector. High quality overheads can be generated on a computer with commercially available presentation software. All of my lecture notes are done this way. I use a laser printer with a large sans-serif font to make overheads. Use of scanners to add graphics and digital cameras to add photographs increases the visual impact of the overheads.
Finding the money to acquire video-microscopes, camcorders, LCD projection panels, laptop computers, and large projection units can be difficult, but they significantly increase the quality of education offered in the large lecture classes. Students write in their evaluations that they want more in-class demonstrations to aid in their comprehension; use your student evaluations with these types of comments to persuade your university administrators to obtain funds for this equipment.
Real-world examples
Many students, both science and non-science majors, complain that what they learn in class does not apply to the real world. They want, and deserve, to see the relevance of the material we teach. We in geology are lucky because so much of what we do is very relevant, and all we need to do is to tell the right "story" at the right time. As in all aspects of teaching, it really helps if you can "live" the example; some of my best stories are of things that have happened to me. Below are examples of some of my real-life scenarios. They are mostly related to mineralogy since that is my specialty.
Relating mineralogy to other fields: We should be able to relate our field both on a broad, conceptual level and more narrowly with individual examples to daily life in our society. Figure 1 is an overhead I use in my class to show how mineralogy can be divided into various subdivisions and how these subdivisions are related to other fields. Most people think of mineralogy as simply the identification of minerals by sight, but this is not how mineralogists spend most of their research efforts. We study crystals by x-ray analysis to determine their crystal structures and visually with microscopes (both electron and optical). These techniques are also used in other disciplines as the arrows indicate. I give examples of my involvement in chemistry (as a post-doc in Switzerland in a chemistry department) and materials science (as a member of an interdisciplinary materials science group at the University of Idaho). I give several examples of work in optical crystallography; optical microscopy is used by forensics scientists (light microscope analysis of carpet fibers helped solve the Atlanta child murder case), the light microscope is used in art restoration and verification, and microscopical analysis proved the image on the Shroud of Turin was hand-painted pigments and not the blood of Christ (McCrone and Skirius, 1980). I tell the students about my experience consulting at Lawrence Livermore Laboratory on their laser optic system used in the test fusion nuclear reactor.
Finally, I present a long list (Table 1) of different uses of minerals. Most of the items in Table 1 should be self-explanatory, but a few need some explanation. There is an active local garnet mine that produces garnet for sandpaper, and gem-grade star garnet material comes from the same area. This is one of the stops on our field trip. We discuss asbestos, which leads into one of the themes of the course, critical thinking and risk evaluation. I explain how zeolites, one of the minerals I research, are used in water purification and had an important role in production of high-octane fuels which aided in aviation during WW II. Some of the earlier color TVs used doped ZnS to arrive at the three needed colors - red, green, and blue. By adding small amounts of other metals into the ZnS structure, electron transitions states are changed and different fluorescent colors are produced on the TV screen. In some of the laser R/W disks, the material on the disk undergoes a phase change when hit with laser light. This phase change causes a difference in reflectance. The two different reflectance values can be read by a light detector and converted to the 0s and 1s of the digital world.
In relating mineralogy to life, many of the examples I use come from my research. I explain to the students how faculty have teaching and research responsibilities and how these two responsibilities, although appearing to be conflicting, really are very synergistic.
Analogy between "waves" to study minerals and the human body: Minerals are made of arrangements of atoms we cannot see, yet we know their location in a crystal structure. The inner core of the earth is solid, but the outer core is liquid. We make these statements about things and places we cannot see or travel to, but how do we know they are true? A good analogy about how we study things which are too small to see (crystal structures) or places we cannot go to (the center of the earth) is the way a physician studies the human body. A physician does not need to perform surgery to see a broken bone or find a tumor; he/she sends "waves" into the body and examines them when they come out. Conceptually, the difference between the two waves represents what the wave passed through - in this case, a human body. Different waves are used depending on what is being studied; for example, x-ray waves, sound waves, and magnetic waves are used in modern medicine.
In geology, x-rays are passed through a material to determine its crystal structure. We can determine the location and arrangement of atoms in the materials based on the effect the material had on the x-rays. The natural waves sent out by earthquakes can be measured after they have passed through different portions of the earth and, with correct interpretation, we can deduce the type of material they passed through.
Pot belly stoves and chemical bonding: In science it is very common to have end members in a system and a continuum between the two. Ionic and covalent bonding provide such an example. Both bond types occur between cations and anions. Ionic bonding is usually explained when the anion "takes" the electrons from the cation and covalent bonding defined as the sharing of electrons. However, in nature there is a continuum between the two. An analogy can be used to explain how electrons behave around a cation and an anion in mixed ionic/covalent bonding. Let two stoves represent the ions. Place the stoves at opposite ends of a cold room and add 5 kids to represent the electrons (Figure 2). The kids will run around the room in a somewhat random fashion, similar to electrons. If both of the stoves are turned on and set at the same temperature, the kids will spend most of the time somewhere between the two - covalent bonding. If one stove is turned on (an anion) and the other off (a cation), the kids will spend almost all of their time huddled around the hot stove - ionic bonding. To have a mixed bonding, the temperature can be varied for the two stoves.
Jeep windshield and Mohs' scale: I relate a somewhat embarrassing personal story to help explain hardness and Mohs' scale. After an ice storm, my wife was scraping the ice from the windshield of our Jeep and noticed the scraper was leaving streaks of aluminum on the windshield. The scraper was old and the hard plastic scraping part was mounted in aluminum. The aluminum came in contact with the windshield, and, because it was softer than glass, it left aluminum metal streaks across it. I got the bright idea to use Ajax to remove the metal streaks. This worked fine, except Ajax contains quartz as one of its abrasives. When the quartz (hardness 7) came in contact with our windshield glass (hardness approximately 5.5), the windshield became very scratched and had to be replaced. I explain that other cleaning agents advertised "safe" for appliances contain feldspars as abrasives.
I then relate how the crystal structures of quartz, feldspar, and glass cause a variation in hardness. The commonality between quartz, feldspar, and glass is that they are all composed of corner-sharing Si-tetrahedron. Quartz is the hardest. In feldspars, some of the tetrahedra Si4+ is replaced by Al3+, causing a charge imbalance and the need for other cations to enter the structure. This explains why feldspar is softer than quartz. Most people think of glass as amorphous, but it is composed of corner-sharing SiO4 tetrahedrons. The tetrahedrons remain intact (i.e., the Si-O bond angles and bond lengths are similar to those in quartz). What changes is the Si-O-Si bond angle (i.e., how the tetrahedrons are joined). There is some randomness to how the tetrahedrons combine in the glass; this semi-random arrangement of the tetrahedrons and some other cations in the glass cause glass to be softer than both quartz and feldspar.
Buying and owning property: What good is knowing where the SW1/4, SW1/4, NE1/4 of S.32, T.40N, R.4W is, or who cares which way the contour lines point along a stream? These are common questions asked when lecturing about topographic maps. In real life, many of us will buy or inherit property; understanding the township and range system allows us to see if the land we think we own is what is in the deed. I checked my mother's deed after I took beginning geology and found a mistake which could have caused my mother to lose her house. The property description indicated she owned not the property on which her house sat but a vacant lot next door, which we thought was owned by a neighbor. Fortunately, the neighbor agreed to change the deed.
Idaho is a rural state, and many of the students will own rural property. An understanding of the township and range system is even more important. When they are in the market to buy land, they will be able to read and understand a topographic map.
Of cows and "polluted" ground water: When I discuss groundwater in class, I tell the following story. My wife and I bought an old house in the hills of southwestern Virginia. When we had the well tested, it had a very high total coliform count, too high to chlorinate. We installed a UV light system on the well to kill the bacteria. We wondered whether the contamination was coming from our septic tank or the cows in the field behind the house and sent a water sample off for more thorough testing. In general, human contamination is much worse than animal. Figure 3 is a map view of the cow pasture, stream, our house, septic tank, and well. The local geology consisted of almost vertical highly fractured interbedded siltstones and sandstone, which created a high fracture permeability. Figure 3 is a cross-section map of what I thought were the flow lines. The sample testing proved the cows caused the contamination, so they were moved to another pasture.
Oil use and interrelation of energy sources: Most people have no idea of the amount of oil we use or import in the U.S. I tell the students we use approximately 15,000,000 barrels a day and import almost one-half of it (N.B. this number and those to follow are rounded and only have 1 or 2 significant figures). This really means nothing to them; it is just a big number, plus what on earth is a barrel? I define a barrel as 42 gallons, which means we use approximately 630,000,000 gallons of oil per day. I suggest they memorize the number of people in the U.S., approximately 250,000,000. Students find it much easier to remember rounded numbers and the significance of the number. After a quick division, we see that we each use about 2-1/2 gallons a day.
It is important for us to know these approximate numbers in order to make informed decisions about energy use and our environment. Is it worth drilling in a wilderness area if the size of the field is only 630,000,000 gallons, one day's consumption? The Exxon Valdez spill was the worst oil spill in America; approximately 8,000,000 gallons were spilled, but this is less than 2% of what we use in one day. We must import approximately 300,000,000 gallons of oil a day. The oil comes in on ships, which means 30-40 supertankers every day all year long must dock somewhere in America. Realistically, we must expect accidents. I conclude by asking them, "Who stopped driving their car the day after the spill?" and note that although many Americans boycotted Exxon they still bought gasoline.
So we use too many hydrocarbons and we create all these greenhouse gases that are going to cause global warming. What do we do? We need to develop alternate energy sources. Nuclear power does not produce greenhouse gases, but it produces radioactive wastes. The point: the solution to one problem usually causes another problem.
Asbestos and other "hazardous" materials: I spend the last two weeks of my course on environmental geology. The students expect to hear about all the bad things we have done to the earth and how ozone depletion, global warming, and asbestos will be the death of all of us. However, I use this time to present facts and try to get the students to learn to critically evaluate risks. I present a case study of asbestos to make the students think about the many similar issues that confront us every time we turn on the evening news. Before asbestos, or any other health-related problem, can be considered significant, an overall knowledge of death statistics in America must be known. Approximately 2,000,000 people die every year in America. Almost 700,000 die from heart disease and 500,000 die from cancers (Almanac, 1992 ). Smoking kills 400,000 (a combination of heart disease and cancers). At worst, 500 people die a year from asbestos diseases (Ross, 1982), but these people worked in the asbestos industry and were exposed to high levels for long periods of time. In some case studies of miners, death rates were no higher than normal. There is much more to the asbestos issue, but it provides an example to the students on how to evaluate a risk in society based upon the facts. Interested readers should see Ross (1982) and Mossman et al. (1990) for a review of the asbestos issue.
No doubt certain materials are hazardous. However, our society has reached a point where almost every chemical is deemed bad. Recently, dust containing above 0.1% quartz was deemed carcinogenic (Ross, 1991). This means every gravel road in America is carcinogenic! We are spending (wasting?) our resources on these non-problems while education, lack of which being the reason the so-called problems exist, is ignored.
Field trip
The field trip is the one of the most important events in the class. It is not required, but I give the students a 1% increase in their final grade if they go. I include questions about the field trip and local geology on the exam, which also motivates them to go.
We are fortunate in northern Idaho to have a fantastic introductory field trip. We make five stops plus a lunch stop on the 5-hour trip. We see the Columbia River basalts, the Idaho Batholith, and the Belt rocks. We collect star garnets from one of only two locations in the world and collect 15 million year old plant fossils, some of which still contain DNA (the oldest known DNA in the world). We also see landslides, canyons, pillow basalts, stream erosion, etc.
The logistics of the 160-mile loop trip with 400 students are a bit more difficult. The major goals of the field trip are to introduce local geology and enable me to interact with all of the students. After the trip, the large lecture hall is much more friendly because of the latter. One week is allocated for the trips. On Monday, I give a lecture on northwest geology and the details of the field trip. Class and labs are canceled for the rest of the week. There are six days of trips. Each day, one group leaves at 9:00 am and a second group leaves at 9:30 am. There are 30-35 students in each trip and we take 3-4 vans. A faculty member leads each trip. I go on the 9:00 am trip and change to the later trip at lunch. The lunch stop, riding in the vans, and the other stops give me a chance to meet and talk with all of the 400 students over the 6 days.
The field trip is a tremendous amount of work for the TAs and me, but it is worth it. The students really enjoy the trip (per their class evaluations) and the trip breaks down the professor/student barrier.
Integrating the above (or avoiding the straight lecture format)
Students get bored listening to 50 minutes of lecture day in and day out, and they need some diversion from the straight lecture format. The in-class demonstrations were my first attempt at doing something other than lecturing. There is a considerable amount of material to cover in any course, but if the students do not learn it (or even hear it, or come to class), we have not done our job.
In the fall semester there are forty-four 50-minute lecture periods. Three lecture periods are used for tests and two are canceled for the field trips, leaving thirty-nine 50-minute periods, or 1,950 minutes to fill. Table 2 lists what is done during lecture time. There is a lecture during every class; all the other activities are integrated into lecture time. When I show a movie it is always at the end of class, and tests are returned at the end of class. The remaining activities occur anytime during lecture.
A brief summary of the data shows that 26 of 39 lectures (67%) have something other than straight lecture. However, lecture time still amounts to 77% of course time. The students really like this approach (based upon comments on their evaluations and personal feedback).
The major drawback to this teaching style is that a considerable amount of time must be spent integrating all of these activities. Another drawback is the technical problems that arise with all of this equipment. We have an excellent support staff that helps with the hardware aspect of these projects.
Testing
Giving tests to 400 students almost forces us to use some kind of computer grading, resulting in questions that must be answered a-e. Most of us dislike this practice, but there is little we can do until class sizes are reduced to 20-30 students where we could give essay style tests, which, of course, would require hiring many more qualified faculty, a trend unlikely to occur. Given these realities, can we find innovative ways to design questions that test the students' knowledge effectively?
I allocate 8 hours to prepare one 50-question test for my class. During the semester there are 4 tests, each which counts 25% of the grade. The final exam is one of these tests and is comprehensive. I structure my tests chronologically, with questions asked in the same order as the material was presented. This, of course, prevents me from making different test forms by randomizing the questions. As stated under the philosophy section, the goal is to help the many and not worry about the few who cheat.
The test is divided into two sections. The first 20 questions are a form of multiple choice (I call "multiple-multiple" choice), and the second is a matching form of fill-in-the-blank, which my students call "Mickey Matching." No questions are taken from the test banks provided with the book. Critical evaluation of these questions shows they are poorly written and usually unclear. At worst, use of these questions is a "cop-out" on the instructor's part!
Table 3 lists examples of questions from a test bank and examples of my multiple-multiple choice and matching. With multiple-multiple choice questions, instructors can ask several questions in one. On the first test I have only two "fill-in-the-blanks" in the questions, and as the students become accustomed to this style of question, I expand to 3 to 4 blanks per question.
The matching is a good alternative to fill-in-the-blank, and it can be computer graded. Each question can be written explaining some geological feature where the students may learn from the question. Another advantage is the students' performance is always better on this portion of the test than the multiple choice, even before I switched to multiple-multiple choice questions. As a class, they will do 5-10% better on this section. That translates to 1/2 to 1 letter grade.
Some explanation is required for the mechanisms of this style of question. There will be 30 blanks to provide answers. A numbered alphabetized list of 40-50 possible answers is provided on a separate sheet. A individual answer can be used more than once or not at all. The students read the question, determine the answer, and then look down the list for it. They then enter the number associated with their choice on a computer scannable form.
Conclusions
This article is intended to share some of the things I have discovered to improve teaching beginning geology. Certain comments made will be agreed upon by many; others might be the focus for debate. All of these ideas attempt to do what everyone (I hope) wants to do, and that is to improve education.
Many of the conclusions I have made throughout this article about the "worth" of a demonstration, an analogy, a testing style, etc. result from student evaluations and personal discussions with students after they have completed the class. The evaluations praise the demonstrations and the overall style with which the course is taught. Of course, the students alone cannot evaluate my teaching - they can only express their opinion of it. To that end, I conclude that the more they like the class, the more they will learn.
Some may find direct use of some of these demonstrations or analogies. However, the main function of providing my own was to stimulate others to develop theirs.
Acknowledgments
I have incorporated many ideas and methods of other professors into my teaching of beginning geology. I would like to thank the following for their specific help, encouragement, and ideas. Prof. F.D. Bloss (Emeritus Alumni Distinguished Professor, Virginia Polytechnic Institute and State University), to the best of my knowledge, was the originator of the question form which my students call Mickey Matching, and instilled in me the importance of teaching and demonstrated how someone can be an excellent teacher as well as an internationally renowned researcher. Prof. John Bush (Associate Professor of Geology, University of Idaho) provided the concepts and logistics of my field trip and is responsible for the balloon example of tetrahedra polymerization. Prof. Scott Morris (Associate Professor of Geography, University of Idaho) provided a considerable amount of moral support and wisdom in teaching large science classes to non-science majors. Prof. George Simmons (Vice Provost for Teaching and Undergraduate Studies, University of Idaho) has given me the opportunity to share my ideas with the general faculty at the University of Idaho; during these presentations and discussions I have been able to focus my thoughts and methods more effectively. Major technical support has been provided by the Division of Instruction Media at the University of Idaho. Last, I thank the students. Their positive feedback provided the motivation for me to try to excel at teaching, and their appreciation is my reward.
References
Almanac, 1992, The 1992 information please almanac: Houghton Mifflin Company, Boston.
Gunter, M.E., 1991, In-class computer demonstrations for physical geology: Journal of Geological Education, v. 39, p. 373-375.
Gunter, M.E. and Downs, R.T., 1991, DRILL: A computer program to aid in the construction of ball & spoke crystal models: American Mineralogist, v. 76, p. 293-294.
McCrone, W.C., and Skirius, C., 1980, Light microscopical study of the Turin "Shroud": The Microscope, v. 28, # 3/4.
Mossman, B.T., Bignon, J., Corn, M., Seaton, A., and Gee, J.B.L., 1990, Asbestos: scientific developments and implications for public policy: Science, v. 247, p. 294-301.
Palmer, A.R., 1991, What should my neighbor (and thus every highschool graduate) know about science: Journal of Geological Education, v. 39, p. 142-145.
Ross, M., (1982) A survey of asbestos-related disease in trades and mining occupations and in factory and mining communities as a means of predicting health risks of non-occupational exposure to fibrous minerals: USGS open file report #82-745.
Ross, M., 1991, Suspect minerals and human health: a commentary. February issue of The Lattice, p. 10-11.
Stadum, C.J., 1992, Geology demonstrations on an overhead projector: Journal of Geological Education, v. 40, p. 215.
Stenstrom, R.C., 1991, Teaching, Research, and Promotion - Is Science Education in Decay?: Journal of Geological Education, v. 39, p. 4-5.
About the Author
Mickey E. Gunter received his B.S. in geology, with a minor in mathematics, in 1979 from Southern Illinois University at Carbondale, and M.S., 1982, and Ph.D., 1987, from Virginia Polytechnic Institute and State University. Currently, he is an assistant professor of mineralogy in the Department of Geology and Geological Engineering at the University of Idaho, teaching beginning geology and mineralogy and conducting research in mineralogy, optical crystallography, quantitative methods in geology, and computer applications in geology.
Table 1: An overhead shown in class listing a few of the important uses of minerals in our society
topic # times # minutes % lecture time
lecture 39 1,510 77
movies 10 190 10
slides 7 140 7
computer demos 4 40 2
return tests 3 30 2
video-microscope 2 40 2
Table 2: A breakdown of how class time is spent.
Question from test bank
S waves:
a. are the same as surface waves
b. travel through solids, liquids, and gases
c. are slower than p-waves
d. are the only waves recorded on a seismograph
e. are slower than surface waves
List the three basic rock groups _________, _________, and _________,
My questions
Example Multiple-multiple choice
Two types of waves generated when there is motion along a fault are: P-waves, or (a)____ waves, and S-waves, or (b)____ waves. These two waves travel at (c)____ velocities and are used to determine the distance to the earthquake. The P-waves travel (d)____ than the S-waves.
1. (a) compression, (b) shear, (c) different, (d) faster
2. (a) shear, (b) compression, (c) different, (d) faster
3. (a) compression, (b) shear, (c) similar, (d) slower
4. (a) compression, (b) shear, (c) different, (d) slower
5. none of the above combinations
Example Mickey-Matching
The rock cycle can be used to explain how rocks are formed, destroyed and altered. Intrusive (23)____ rocks form from crystallization of a/an (24)____; (25)____ rocks form from lithification of (26)____; and (27)____ rocks form from alteration in the (28)____ state of existing rocks.
Portion of an alphabetized and numbered list of possible answers for the above:
1. basalts 1. lava 1. molten 2. fayalite 2. limestones 2. sedimentary 3. gaseous 3. liquid 3. sediments 4. igneous 4. magma 4. solid 5. Jurassic 5. metamorphic 5. solution
Table 3: Example questions taken from a test bank and modifications of these questions to aid in evaluating what the students know.
Figure captions
Figure 1: A diagram showing how mineralogy is a subdiscipline of geology. Mineralogy can also be further divided and those divisions can then be related to other fields.
Figure 2: An analogy between stoves and kids and atoms and electrons in chemical bonding.
Figure 3: Map view (on left) and cross-section (on right) of ground water contamination on our property in Virginia.
Figure 1
Figure 2
Figure 3
