An approach to distance-learning courses based on streaming audio and vector graphics
University of Arizona, Tucson, AZ
University of Arizona, Tucson, AZ
I would like to describe an approach that we have developed for distance-learning geo-engineering courses at the University of Arizona, culminating in the development of an online geomechanics course with a virtual rock lab that will debut in 2001.
First a little history… Since 1990 I have been co-teaching a general education course about Earth’s resources and the environment with Dr. Mary Poulton. Starting in 1995 a technology component was added that consisted of teaching multimedia skills to the students and having them use these skills to develop multimedia projects. Starting in the Fall of 1998 the University of Arizona completely restructured its general education curriculum. At that time we converted the Earth resources and the environment course into a new web-assisted course for the general education program, NATS 101. The course regularly has over 200 students each semester. The web site contains all of the course content and allows most of the traditional lectures in the course to be replaced by in-class activities and computer labs. Only about one out of three lecture hours are used for traditional lecturing. The web site makes extensive use of Flash animation (animation made using the Macromedia program Flash) for dynamic web pages, interactive question/answer and calculation elements, and database functions. The web site also makes some use of streaming video. Mr. Zeitler was the primary web developer for this course. Like the original course, we still teach multimedia skills to the students, in this case, web skills. Students use these skills to maintain a home web page on which they post writing assignments. We have seen an increase in the quality and professionalism of the students writing assignments due in part to the fact that their peers and even their parents can see their work!
Based on our experiences with the Earth resources and the environment course, starting in 2000 Mr. Zeitler and myself took on the ambitious task of converting a geomechanics course that I have been teaching for 10 years into a distance-learning course. This course includes in-class lectures and a weekly rock mechanics lab. Like many geology and engineering courses, the lectures utilize a whiteboard for derivations, problem solving and drawings; an overhead projector for graphs and tables; and a computer projector for high-resolution images, video and the demonstration of computer software. Interactivity is another important element of the classroom experience. One of the challenges in developing the online course was to develop an approach that can effectively capture these classroom elements. In addition, the rock lab provides a hands-on, kinesthetic experience for the students, as well as a writing experience in the form of laboratory reports. The second challenge was to develop an innovative approach to capture these important laboratory experiences.
There are a number of current approaches being used for online course delivery. The most common approach focuses on text and graphics, much like a traditional textbook. Other approaches utilize streaming video synchronized with Microsoft PowerPoint slides, or animated simulations utilizing Macromedia Flash or Director. All of these methods have advantages and disadvantages for specific applications. None of the techniques can adequately handle the kinesthetic aspects of a laboratory course. In an attempt to address the deficiencies of some of these approaches, a new approach was adapted for the online geomechanics course as described below.
An approach based on streaming audio along with animated vector graphics has been adapted for the lecture portion of the course. The streaming audio is recorded from actual lectures using a digital audio recorder. The audio requires 5% or less of the bandwidth required for streaming video, thus greatly reducing the transfer time over the internet. Vector graphics are used to represent all the material written on the whiteboard. They are animated so that text, equations and drawings appear on the whiteboard in synch with the audio. Vector graphics have bandwidth advantages over raster graphics and in addition vector graphics can be scaled without loss of resolution. In addition to streaming audio and vector graphics, an additional window is present in the interface to view high-resolution graphics and video. Finally a third window in the interface gives access to a server-based discussion forum so that students going through a lecture can pause and pose a question or review a database of previously asked questions before moving on to new material.
The integration of the streaming audio, vector graphics, and the high-resolution graphics and discussion forum windows is made possible through the use of Macromedia Flash and Active Server Pages (ASP). Digital audio from the lectures is first edited for clarity and then imported into Flash in WAV format. Flash provides a number of intuitive tools for adding vector-based text, lines and shapes and allows for easy modification of their size, color, and position. These vector elements are added to the movie at the appropriate locations so that the appearance of objects on the screen are synched at the correct time in the audio stream. The completed files are then exported using MP3 audio compression at a bit rate of 16 kbps. This compression setting is typically used for voice recordings and streams easily over a 28k modem connection. When a student requests a lecture module, the ASP files obtain these configuration parameters for the corresponding Flash movie and dynamically generate the virtual lecture interface for the selected module. The current module is embedded in a static controller flash movie that allows the user to navigate between modules without having to reload the entire interface. This controller movie is dynamically configured by the database parameters and the intrinsic properties of the Flash module. ASP files are also used to dynamically generate the window containing high-quality video and raster graphics when called by the Flash module. The discussion forum is also based on ASP files that generate both the relevant discussion content and a Flash element that allows for searching, navigation, and configuration of user profiles. The discussion forum was built on a Freeware discussion platform obtained from Snitz Communications (http://forums.snitz.com).
There are many advantages to the approach described above. First of all, vector graphics can expand or shrink without loss of quality, and the interface has been designed to expand to the size of the current monitor. This creates a readable, user-friendly interface on large monitors, which would not be possible with streaming video. Secondly, the streaming audio and animated vector graphics together require only 5-10% of the bandwidth needed for a 320 x 240 streaming video window. This allows the lectures with our approach to stream perfectly over 28k modem connections. Thirdly, this approach provides a high-quality learning environment that caters to the same learning styles as those of a traditional science lecture. All of the elements of a traditional science lecture, including equations, drawings, graphs, images, and video, can be incorporated into this approach. Finally, it is relatively easy to transform a traditional class into an online course using this approach.
The laboratory serves several purposes for the student. Most importantly, it provides a hands-on or kinesthetic experience for the student, and allows the student to learn in a way not possible in the standard classroom. It also provides useful skills that the student may use after graduation or in other classes. Thirdly, students collect data in the lab that is subsequently analyzed, interpreted and written about. A virtual lab will never replace a hands-on lab. However, the virtual lab can cater to as many of the kinesthetic, analytical, and writing experiences as possible.
An innovative approach has been developed for the laboratory portion of the geomechanics course based on streaming video of actual demonstrations of laboratory procedures, along with a “rock-breaking simulator” that allows students to obtain a unique set of data on a particular test that can be subsequently analyzed and form the basis for a laboratory report.
Digital video recordings were made for eight standard rock mechanics tests: point load, Brazilian tensile, Uniaxial compression (with and without strain gauges), Triaxial compression, direct shear, P and S wave velocity, and slake durability. This includes the sample preparation, setting up the testing apparatus, the testing, and some of the post processing of the data. The digital video is broken up into two-minute segments and compressed with the three common video formats, QuickTime, Real, and Windows Media. In addition, both high- and low-resolution versions are made. The low-resolution version allows streaming on 56k modems.
A student is expected to watch the video for a particular test and then obtain unique data on that particular test using the rock-breaking simulator. The rock-breaking simulator was produced using Macromedia Flash, and reads statistical information about a certain rock outcrop from a user-defined database. For a granite outcrop that may be a site for an underground excavation, for instance, the database includes rock type, the mean and probability distribution for each of the tests, the spatial variation in the properties, and other site information. Each time the student “breaks” the rock, the simulator picks from the probability distribution for that rock and test type and supplies a unique value. Students then analyze this data and the results form the basis for written reports.
References on the NAT 101 course:
Web site: http://www.fcii.arizona.edu/poulton/nats101
Kemeny, J., Poulton, M. & Zeitler, B., NATS 101: A Geo-engineering general education course with synchronous web and classroom delivery. Proceedings of the ASEE Pacific Southwest Section Spring Conference, University of Arizona (2000).
Poulton, M & Kemeny, J. A model for integrating technical preceptors in the classroom. In J.Miller, J. Groccia, M Miller (eds), Student Assisted Teaching: A Guide to Faculty Student Teamwork, Anker Publishing, Bolton, MA. (2001).
References on the Geomechanics online course:
Web site: http://www.fcii.arizona.edu/MNE527 (sample lectures)
Kemeny, J. and Zeitler, B. 2001. An Online Geomechanics Course with a Virtual Rock Lab Based on Streaming Audio and Vector Graphics, Proceedings of the 2001 American Society for Engineering Education Annual Conference & Exposition, American Society for Engineering Education.
Kemeny, J., Zeitler, B., and Murphy, R. 2000 (abstract). An Online Geomechanics Course with a Virtual Rock Lab, GSA Annual Meeting, Reno, NV.