A Digital Boost to Petrographic Learning

In an effort to more actively engage students in petrology and to increase the efficacy of student learning, we recently outfitted each student's petrographic microscope with a relatively inexpensive (~$200) digital camera linked to a pen-tablet computer. The camera-tablet systems assist student learning in a variety of ways. Capturing an informative digital illustration and annotating it with digital ink or computer graphics tools emulate essential features of more traditional line drawings (visualizing an appropriate feature and selecting a representative image of it, internalizing the feature through studying and annotating it) while minimizing the frustration that many students feel about drawing. The images can become part of a virtual mineral/rock/texture portfolio tailored to individual student's needs. Digital images also allow real-time assistance with and assessment of students' observational acuity: both instructor and student can simultaneously see the same petrographic features and exchange information about it by pointing to salient features using the tablet pen. Camera-tablet systems can also be used for collaborative learning. We have distributed observational responsibilities among individual members of teams. The students then use annotated digital images to share their findings and arrive at an understanding of an entire rock suite. This interdependence increases the individual's sense of responsibility for their work and the reporting out encourages students to practice use of technical vocabulary and to defend their observations.

In a post-course survey, the majority of students reported that, if available, they would use camera-tablet systems to capture microscope images (77%) and to make notes on images (71%). An informal focus group recommended introducing the cameras as soon as possible and having them available for making personal mineralogy/petrology portfolios but, because the stakes are perceived as high, using them selectively for peer-peer exercises. Better cameras may be required for high quality visualization work.