1.3.2 Software Development

The software developed in the proposed effort will be based primarily MOSAIC, an existing software package. This will reduce development costs and assure easy access to the wealth of material already available in HTML (HyperText Markup Language) documents which have been and will be produced by NASA and other scientists. MOSAIC is an Internet information browser developed at NCSA (National Center for Supercomputing Applications) which displays formatted text, images, sound, graphics, and movies. It also supports Internet navigation through hyper-text links (via clicking on marked text) and through images (via clicking on "hot spots" in the image). We will implement the group-learning aspect of "Windows to the Universe" using existing software capabilities as well. A Common Client Interface capability is currently being developed and tested at NCSA for MOSAIC. COLLAGE is an alternative software package (also developed by NCSA) which could be used to support group-learning activities. Either package supports collaboration through multi-person multi-site viewing of text, images, and drawings. These two software packages will be evaluated to determine which is optimized to meet the requirements of the group-learning aspect of our project.

Learning often best takes place when one person guides another or when multiple people explore an environment together. To this end, we will include a group learning mode in the application so that a click on a link at one site can activate a simulated click on a link at all companion sites in a group. Thus, several people can join in a group (regardless of their location) to navigate hyper-text and image links together. As part of this extension, the group membership mechanisms will be modified to support read-only membership. Thus, it will be possible to have "leader" and "follower" members, supporting many different styles of group interaction. For example, in a traditional lecture style, one leader guides a number of followers, while in another style of group exploration, all members of the group are equally leaders.

To allow the greatest utilization of the system by the general public, software development will occurs on multiple computer platforms in a phased development. The platforms are Macintosh, PC's, and UNIX machines. Initial development will be done on the Macintosh version of MOSAIC and then migrated to the UNIX X-windows version, and finally to the PC version. In initial development, the application will be optimized for an ISDN modem connection to the Internet running on Mac Power PC 6100 class platforms (funding for this equipment is requested in the budget). Testing will be performed to assess the impact of slower baud rates (v.32bis) and lower level platforms (Mac IIs) on application performance, with the intent of designing the application to run effectively over a range of platform classes and baud rates. A "bullet proof wrapper" will be placed around the resulting software which will provide a greatly simplified user interface, suitable for a "hands on" setting. In particular, the mechanisms providing the ability to form groups will be simplified so that a knowledge of port numbers and IP addresses is unnecessary.

A usable prototype of "Windows to the Universe" will be produced and placed for testing and user feedback by the end of the first six-month period. Rather than design the entire system, then code and test it, we will design, code, and test in parallel. Thus, user feedback will become part of the design early in the development. Revisions of the software will be deployed for continued testing and evaluation at six month intervals. This approach has been used successfully in many of the applications that have been developed on the Internet, where early versions of the application are released to users to try out and comment on. A home page will be maintained throughout project activities on one of the RSD Project Internet servers with hypertext links such that any interested parties can access information on the project, the status of the project, and work in progress. The final version of the application, along with documented code, object files, and executables, will be delivered as public domain software .