Over the past couple of years, a very powerful movement has been growing throughout higher education. We, as instructors, are being asked (perhaps forced, in some cases) to expand use of the Web for teaching and learning. The "Web" train has left the station and it is gaining momentum. But is using this evolving technology a good or a bad thing? If it is a good thing, exactly what should we be doing? How should we be doing it? Before jumping on (or off) this train, we need to step back for a moment and try to answer some fundamental questions about this revolution and about how and what we teach and how students learn.

Probably the most basic question is "why?" Why develop Web resources for teaching and learning? The answer to this is easy: The Web can be used to provide up-to-date and relevant course materials and activities to large numbers of students in many cases more efficiently and in some ways even better than more traditional methods.

How is the Web being used for learning? Some web materials are course-administrative in nature. This is what students usually want to print: course syllabi, sample tests, keys to quizzes, course notes, field trip guides, glossaries, and so on. These can be important parts of a course and the Web is a bood mechanism for distribution, but these supplementary materials, in themselves, contribute little to learning. A second category of materials commonly found on the Web is hypertext/multimedia. This material is like an encyclopedia which contains information which the user can read, links that can be followed to other text or pictures or sounds and more material to read. Again, these materials can be important parts of a course, but should be used with the understanding that they can only engage students superficially. Finally, there are those web sites that actively engage students in the processes that foster learning. I like to compare these web activities with a hands-on geology lab. In a traditional, well-designed geology lab the student observes, measures, records, synthesizes and hypothesizes: all activities that generally are considered essential for learning. Imagine how boring and ineffective the learning would be in a mineral identification lab where the student looked at pictures of minerals and had to read text listing the physical properties of minerals. A better lab activity would likely have students handle minerals, measure properties such as specific gravity and hardness, describe cleavage and luster, and then organize these data and refer to determinative table for possible identification and classification. To be an effective learning tool, the Web must, like the traditional hands-on lab, enable students to be "active" participants in their own learning. Actively "doing" enhances learning. Simple, discovery-based learning actually works. The Web must move beyond hypertext/multimedia documents that are archives of an instructor's course notes or supporting materials and be used to provide the inquiry-based activities that promote understanding, discovery, and creative thinking. Web sites can be designed so traditional geology labs can be modeled and, more interestingly, so that students can themselves conduct classical scientific experiments or interact with simulations of dangerous or expensive or long time-dependent processes (such as evolution or plate tectonics) not easily studied using more traditional means. The possibilities are enormous. Unfortunately, most geology-related Web sites are missing this essential interactivity.

How can web materials be made interactive? Web browser and server software has now evolved to the point where meaningful interactivity can be achieved in a number of amazing ways. Server-side CGI scripts can produce new documents on the fly in response to remote input from the user. Distributed Java applets and JavaScripts can enhance a web page with dynamic content so that students are "doing" more than just pointing, clicking, and viewing. These web-based, interactive multimedia capabilities present an enormous pedagogical potential that is just beginning to be exploited. Recently, I helped develop two examples of web-based, interactive applications as models for on-line geology labs: Virtual Earthquake (VEQ) and Virtual Dating. VEQ executes CGI scripts on a web server in response to student input through HTML forms. On any given day about 400-500 students from across the country work through the Virtual Earthquake activity which is about how epicenters are located and how Richter's magnitude is determined. Virtual Dating, which models radiometric age dating, is in BETA release and relies mostly on Java applets and JavaScripts as a basis for interactivity.

What about difficulties and liabilities? How difficult is it to develop these on-line labs? Generally, it's not easy. The important issues of content and pedagogy can be addressed by most geology faculty. But the modern scripting languages require expertise not normally at our fingertips. Initially, I had help from a knowledgeable colleague, and I'm now CO-PI on an NSF grant which supports a full-time programmer and a part-time graphics artist. Even with expert help, it still takes a lot of time to design, develop and implement activities like Virtual Dating or VEQ--perhaps a year or more. One frustrating aspect of the development process is that the technology keeps changing. The current round of "browser wars" is an example. Furthermore, users have a serious drawback if they lack Internet access or have insufficiently powerful computers to execute the applets or scripts. Of course, many of these drawbacks are balanced by the ease of dissemination. Once something is on the Web, it is there for everyone. Also, changes and updates to a site are instantaneously available to all.

A final question concerns assessment. Is developing interactive Web-based on-line labs worth the time, effort and expense? Are students learning? Yes, they are. The high number of students assigned to complete VEQ is a good indication. A survey of 40 instructors using VEQ concludes that 85% of the instructors say VEQ improves teaching, improves learning, and speeds up learning. Ninety percent say it makes learning more fun and all (100%) indicated that they want more on-line interactive web-based labs. There are a number of interactive sites currently under development that may be appropriate for geology instruction. You don't have to develop your own site, but I encourage you to build meaningful activities around these interactive sites as they become available. As a developer, myself, I hope you will provide abundant feedback to the people trying to bring interactivity to the Web. It really helps with the process.

There will continue to be growing pressures for faculty to develop and use Web-based tools and courses. There are many challenges associated with the process as well as a lot of hard work and needed resources. However, some great things can be done, especially with interactive on-line labs. If these are done right, students will benefit and have fun as they learn. The Web train is moving and, willingly or not, you are likely to be on that train. You don't have to be an engineer, but as a passenger you should give some thought to its destination. What goals do you envision for your students?