Online Oceanography

Technology

<Index><Next Slide>

Technical Philosophy

The GeoEd Online software is powered by MacroMedia Director and Shockwave. The advantage of this over other solutions (e.g. Java, Javascript, etc) is ease and flexibility of programming. Director uses a scripting language called Lingo, which is extremely flexible in the way it supports network, graphics, text processing, and other multi-media needs. It works on Macintosh and PC platforms in both stand-alone and browser environments.

Another advantage of the Director/Shockwave approach is that most processing is done on the client's machine, rather than the server. Other approaches rely on a powerful server resident database program to create web pages for each task. In contrast, the server-side cgi for GeoEd is quite simple, only writing files, returning file and directory lists, returning matching items from a delimited list, etc. This simplicity enables dissemination at low cost, instead of forcing the adopter to purchase an expensive database system. Of course, Director is capable of interfacing with server resident databases and commercial class management software.

Browser or CD-ROM Delivery?

The GeoEd software can be accessed through either browser or from a CD-ROM. The advantage of browser delivery is easy access by learners, and quick updating in case of errors. The disadvantages are that download times can be significant for dialup internet access, and browser security features create barriers that limit critical functions. Stand-alone operation allows integration with software to display large datasets residing on a local CD-ROM. Automatic updating of software can be implemented, so that bug fixes and improvements can be disseminated easily.

GeoEd was first implemented for browser access. This worked well for online homeworks and grade calculations. However, as the project became more complex, a CD-ROM was chosen to simplify access to the student's desktop. Capturing and uploading graphics was the primary concern, as was integration with the "Our Dynamic Planet" software. Automatic updating was not implemented, which made it difficult to upgrade software when improvements or bug fixes were needed. For a project like this, where software is being developed with limited resources, quick upgrading is essential. Fortunately, Director supports this capability.

<Index><Next Slide>