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Customized information access and dissemination greatly enhances the power of the Web. This requires not only tailoring the user interface and the information presented, but also tailoring how the information is presented based upon the identity of the user, level of access, or stored user preferences. MITRE's Internet Technologies group has investigated and implemented various tailoring schemes for a range of sponsor and internal applications. These include MITRE's Air Force Center (AFC) Daily site and the rebuilding of our dynamic, internal phonebook application using the new suite of X-technologies: Extensible Markup Language (XML), Extensible Style Language (XSL), and Extensible Query Language (XQL). Internal Site with Secure External View AFC Daily is an internal MITRE Web site supporting dynamic communication among the 1,700 members of MITRE's Air Force Center. It consists of four news-style pages created from news items submitted via a Web form. Whenever a new news item is received, the page is automatically updated on the server, cached, and then served to end-users accessing the page. Using internally developed extranet technology that allows secure and controlled external access through the MITRE firewall and into the site, we developed a secure external-access capability prototype for internal sites. In this case, it involved giving our Air Force sponsors access to a subset of the news items tagged as releasable. We did this by first flagging the appropriate news items as "sponsor-accessible" in the access control field. By default, all of the static links on the site were made inaccessible to the external user unless specifically approved as accessible. The challenging part was in the user interface presentation. Although the content at the destination of a text or graphic link would not be accessible to a user, visually the links appeared to be accessible. Of course, forcing a user to click on a link to determine if it is accessible is not good interface design. And while text links could be removed entirely, partially accessible image maps remained a problem, as well as removing graphic links that might leave unsightly holes on the page. There was also the difficulty of replaceing a page element or feature with another on the sponsor view. Finally, the page had an internally oriented look and we wanted a page with a sponsor-sharing orientation for that view. Some of these problems were solved with custom extranet tags put into the page source to allow or deny customer access to various elements on the page. For instance, the tag: <xtranet aclname="denyFFRDCsponsors"> prevents elements listed below it from appearing on the page. However, while this scheme provided the necessary tailoring of information access and presentation for each user group, it was cumbersome. The page source is essentially two page designs mixed together, and making a change to the source for one page could inadvertently affect the other. It also requires that both views be re-tested after each change. From our work here, we believe that it would be cleaner and easier to maintain this type of site if we utilized style sheets. Phonebook Application Employs X-Technologies When we rebuilt MITRE's internal phonebook application, we employed the new X-technologies to address the issues discovered in developing the AFC Daily site. The new internal phonebook allows users to look up information associated with MITRE employees, services, internal mailing lists, and internal organizations and projects. While building the application we planned multiple tailored versions: (1) the internal MITRE employee view, in detail view, (2) internal MITRE employee view, in summary view, (3) owner's view, so the owner of a phonebook page could have additional edit capabilities, (4) internal contractor view, in which a different limited subset of data would be available, and (5) external user view, in which a very limited subset of data would be available on the MITRE external server. Using an architecture based on XSL, XML, a Lightweight Directory Access Protocol (LDAP) server, and Java servlets, we applied XSL to the XML-formatted data on the server to produce the HTML output returned to the client for the various desired views. To change a presentation feature or to add or subtract a data item in a particular view, we merely modified the particular style sheet. The result was a very clean and modular design that is easy to maintain and edit. Creation of new views requires minimal or no interaction with other parts of the code, and there are no longer usability issues associated with displaying elements that are not accessible to a particular user group. Currently, the MITRE phonebook only uses two of the views for the data - the internal MITRE employee summary and detail views. Tailored views, based on a user's group membership are currently not supported in the operational environment because we do not yet require user authentication to access the operational phonebook. However, we have developed and successfully tested another view that requires this process on our intranet beta server. The test provided an owner's page view as well as the two standard internal employee views. This same technology is being applied to a site being created for one of our sponsors, in which multiple views based on a user's group membership are being implemented. Realizing Fully Web-Personalized Information Delivery The next step in realizing fully Web-personalized information delivery is to allow users to set their own preferences on how they want information presented and to store default behaviors associated with various applications. Ideally, this information would be stored in a distributed manner as opposed to on a site-by-site basis. MITRE is currently researching how to create a "distributed profile service" to facilitate personalized information access, brokerage, and delivery utilizing the X-technologies (see diagram). The XML formatted profiles provide easy accessibility and support a loosely defined schema. For users, this will allow a single input of preferences for a particular domain, and it provides control over who retrieves that profile information. For information producers, this will support access to potential new clients and provide an interface to a single source of client information. This capability, combined with XSL for customized presentation, will provide for fully customized Web user interfaces. Internal Phonebook High Level System Diagram For more information, please contact Donna Cuomo using the employee directory. |
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