A tutorial for sandstone petrology: Architecture and development of an interactive program for teaching highly visual material

We have developed an interactive computer-based tutorial in sandstone petrology for undergraduate-level students. The goal of this tutorial is to provide students exposure to the highly visual subject matter of petrography outside the confines of organized laboratory exercises. This paper describes the architecture and development procedures of the current version of the sandstone petrography tutorial, and offers a possible model for similar development approaches in other fields of petrography or in any other field that utilizes large quantities of visual material such as remote sensing image interpretation or seismic interpretation. The tutorial is an interactive photomicrograph archive with sufficient content and flexible architecture that functions as a virtual laboratory instructor as well as a stand-alone reference. The current tutorial was programmed using Macromedia Authorware v.6.0 and supports both Windows-based and MacOS personal computers. The tutorial is constructed around the Folk sandstone classification scheme (quartzarenite, arkose, and litharenite), and an additional section addresses grains other than quartz, feldspar, and lithic fragments and sandstones dominated by these grains. The user interface is designed to take minimal portion of the screen area so that the screen can closely mimic the type of view seen by a student peering down a microscope. Each photomicrograph in the tutorial is basically unadorned until the user actively calls up information that is temporarily displayed over the image, inducing the user to search for information and actively "ask" to be informed with a mouse click. The structure of the tutorial permits multiple strategies of program use, as a linear tutorial, tutorial driven by thumbnail browser, and as a searchable reference.