Petrographic data is obtained principally in the form of visual information (images). Petrography fundamentally remains a qualitative field of study in which various aspects of rock history are interpreted by a trained observer from features observed at the microscopic scale. Instruction in petrography is still practiced primarily in a manner unchanged since the nineteenth century. Petrography instruction involves mostly cognitive learning domain: students are instructed and drilled in identification of various features seen under the microscope, trained to comprehend the meaning of features identified, and synthesize these observations and significance to evaluate the value of the specimens. By providing carefully designed courseware containing hundreds of interactive virtual specimens with exemplary observations and interpretations, and combining these content with self-assessment quiz modules for self-paced diagnosis and evaluation, the proposed carbonate rock tutorial module will allow students to gain high levels of expertise with description and interpretation of carbonate rocks in a highly efficient manner.
The proposed tutorial is targeted for use in laboratory portion of upper level geology courses such as 'General Petrography', 'Sedimentology', 'Sedimentary Petrology', and 'Sedimentary Petrography'. On-line investigation of randomly selected 344 geoscience departments out of approximately 500 geoscience departments in North America (http://www.usd.edu/esci/geodepts.html) indicates that 82% of these departments include coursework specific to sedimentary rocks, thus it is reasonable to state this topic is an essential component of a geoscience education. In addition, this proposed tutorial could be selectively used in lower level geology courses, Earth Science, and Environmental Science courses, thus potentially benefiting far wider student population in similar disciplines.
Maintaining a role for petrographic studies in the modern geoscience curriculum requires that new, more efficient methods be devised for passing skills from instructor to student. This proposal describes a multimedia carbonate rock tutorial that will attempt to mimic the visual and interactive character of traditional petrographic instruction. Development and evaluation of the tutorial will take place in connection with an established upper division undergraduate course at the University of Texas at Austin.
Ever since Henry C. Sorby, the 'father of petrography', introduced microscopy in geological research and published the first paper based on such work in 1851 (Folk 1965), the teaching methods of petrography have remained practically unchanged. In conventional practice, an instructor having extensive petrographic experience conducts a laboratory through demonstrations to a small group of students. After watching the demonstration on how to locate and identify a given feature, the student is called upon to make such an identification independently, and to have the correctness of their interpretation confirmed by the instructor. Typically, this proceeds through a repeated exchange in which students locate a feature, question the instructor about it, and in turn are interrogated about other features located by the instructor.
Petrography instruction involves mostly the cognitive learning domain: students are instructed and drilled in identification of various features seen under the microscope, trained to comprehend the meaning of features identified, and synthesize these observations and significance to evaluate the value of the specimens. Petrographic expertise with microscopy is attained through repeated exposure to large amounts of visual information. Teaching of petrography necessarily depends upon the involvement of an instructor who has already attained this expertise. In carbonates, as in all natural materials, tremendous heterogeneity of form exists across features of equivalent classification. Hence, expertise with identification of rock components requires repeated exposure to a wide range of examples. Extensive practice outside of the laboratory is a key element to gaining petrographic expertise, but especially at the beginning of this process, individualized attention from the instructor is indispensable. Accomplishing petrographic instruction depends not only upon the availability of an experienced petrographer and but also on the availability of suitable demonstration materials (thin sections) and working petrographic microscopes. It is inescapable that instruction in petrography is labor-intensive, and therefore expensive. Further expense relates to the cost of microscopy equipment and thin sections.
In order to complement the labor-intensive nature of petrography teaching, traditional hard copy image atlases (e.g. Scholle 1978; Scholle 1979; MacKenzie et al. 1982; Adams et al. 1984) as well as image archives on Photo CD (Carozzi 1996) have been used in undergraduate petrography laboratory exercises. In addition, since the mid-1990's, from the advent of the Internet as a viable medium for conveying educational resources (Butler 1998; Butler 2000), web pages have been constructed to provide petrographic images and related information (e.g., Perkins and Hartman 2001; Choh et al. 2002, Table 1). Though convenient sources of information, the biggest shortcoming of these traditional hard copy and electronic atlases is that identification of individual components within a complex image can be troublesome for the novice user. These existing archives do not deliver effective pedagogy for learning petrography because they do not provide substantial informational content keyed to specific areas of the image. In order to overcome these obstacles, the construction of an interactive photomicrograph archive with sufficient content and flexible architecture that functions as a virtual laboratory instructor as well as a stand-alone reference is proposed.
The goal of this proposal is to develop multi-media 'virtual petrography tutor' in carbonate petrology. The subject content of this tutorial relates to the particular expertise of the P.I.s, but the development methods and the educational assessment are broadly relevant to any area natural science in which learning centers on exposure to large quantities of visual information. The proposed instructional module will: 1. Expose students to a quantity of petrographic information comparable to that formerly provided in laboratory activities that have been largely displaced from the curriculum; 2. Allow students to efficiently gain a higher level of expertise in rock description than the current curriculum permits and, 3. Motivate students to persist in higher-level petrographic studies.
The proposed tutorial will expose the students to a carefully designed large and diverse amount of visual material based on the analysis of student learning styles. In contrast to existing image atlases (e.g. Adams and MacKenzie, 1998; Carrozzi, 1996; Scholle, 1978; Scholle, 1979), the tutorial will contain substantial interpretive material, an interactive structure, and most importantly, a structure that will promote sequence of cognitive development that will guide the student through a process that will itself promote absorption of the information.
The proposed carbonate tutorial is going to be a self-contained unit meticulously crafted to function as a single coherent product. A student self-assessment test engine will be built so that students must evaluate their progress by taking a quiz following each tutorial segment. Assessment questions will measure the degree of cognitive attainment in multiple formats, utilizing multiple choice, single choice, true-false, and choosing-the-right-object questions. This self-paced assessment module will be the key feature for controlling the sequence of cognitive development. Level 1 quiz will focus on individual grain and diagenetic feature identification. Level 2 assessments will be centered on relating petrographic observations to its significance. Level 3 assessment engine will primarily measure the student user's ability to analyze and apply petrographic observations and its significances. The student user will receive immediate feedback and suggestions for further study. 35~45% of the tutorial images will be available for the quiz database.
Assessment activities will be carried out under the direction of Dr. James Barufaldi (UT Center for Science Education) during two offerings of the course, GEO 416M, Sedimentary Rocks. Students enrolled in this course are geology majors and petroleum engineers, most in their second or third year of the program. The goals of the assessment are: 1. Identifying problems with student learning in sedimentary petrology that needed to be addressed, 2. Functionality of the tutorial design and architecture; 3. Student impressions about the utility of the tutorial; and 4. actual content attainment. During the fall semester (2004) the students will not be provided with the carbonate petrology CD. During the spring semester (2005), CD copies of the digital tutorial will be distributed to all the students. The teaching assistants will use the CD to demonstrate petrographic features at the beginning of laboratory exercises. A desktop computer running the tutorial will be available during laboratory activities. Students were encouraged to utilize the CD as a study aid and to respond to a detailed questionnaire relating to their experiences with the tutorial. Interviews with randomly selected students will be conducted.
The carbonate petrology tutorial is designed for use in laboratory courses such as 'general petrography', 'sedimentology', 'sedimentary petrology', and sedimentary petrography that cover microscopic examination of sedimentary materials. At The University of Texas at Austin, such a course, GEO 416M is offered twice yearly to enrollments in the range of 60-100 students each semester. Students enrolled in GEO 416M are typically sophomores and juniors and include geology majors (50% of the enrollment) who have had an introduction to optical mineralogy as well as petroleum engineers (40%) and others (10%) who have not had such an introduction.