Date: Tue, 10 Dec 1996 22:42:53 GMT Server: NCSA/1.4.2 Content-type: text/html Last-modified: Fri, 12 Jan 1996 00:44:25 GMT Content-length: 7215 Wtutor

Wtutor

The World Wide Web is a rich source of material that can be used for educational purposes. Advantages of reusing these existing materials are avoiding the duplicated effort of creating new versions of material that is already in existence, using up-to-date information, and letting the student see the original source materials. In addition this approach permits tutorial authors to focus on adding value by organizing, commenting on, and adding to existing information.

The World Wide Web provides a vast store of globally available information from a variety of sources. Government agencies such as the National Institute of Health, NASA, and the Smithsonian operate multiple Web servers that allow access to data, reports, art and analysis. Most universities and colleges have Internet access and these institutions, their departments, faculty, staff and students have set up Web servers to provide information about the schools and their research. Organizations such as CERN make specifications and proposals available via the Web. Businesses and individuals operate Web sites for self-promotional purposes or for love of a subject. All of these different resources can be used to find materials for inclusion in tutorials.

Using existing materials from the WWW for educational purposes presents a number of problems that must be dealt with. The first problem is the filtering problem: with all the material out there on the Web, how does the student know which materials are relevant to the chosen subject area? And of those relevant materials, which best present the subject at a level appropriate for the student? Once the set of appropriate materials has been selected the student is confronted with the navigation problem: given the set of appropriate materials, where should the student start? In what order should the student view those materials? When is the student finished?

Wtutor is a system that allows a tutorial author to create tutorials as trails through WWW documents and include assessment points along the trail. Wtutor monitors the student’s progress through a tutorial and provides guidance to the student as well as feedback regarding the student’s performance on the assessment points.

There are four major components that make up the Wtutor environment: the Wtutor program, the Tmosaic program, a tutorial map and the World Wide Web. Wtutor is an Allegro Common-Lisp program which runs on a Sun workstation. Wtutor interacts with Tmosaic and the tutorial map.

Tmosaic is a modified version of NCSA Mosaic. Tmosaic provides the interface to the World Wide Web; it is used to retrieve Web documents and display those documents to the student or tutorial author. A socket and corresponding message protocol were added to NCSA Mosaic so that Wtutor could communicate with Tmosaic. Tmosaic notifies Wtutor of events such as retrieval of a URL, submission of a form, and student requests such as Next URL. In turn, Wtutor can pass requests to Tmosaic such as Load URL.

The tutorial map defines the tutorial to Wtutor. Logically, the tutorial map is a directed graph, where the nodes of the graph are URLs and assessment points and the edges of the graph are precedence relationships between the nodes. Wtutor uses the map to guide the student through the tutorial. In the Wtutor environment, the primary role of the tutorial author is to create the tutorial map. The tutorial map identifies all the URLs within the tutorial, thereby eliminating the filtering problem for the tutorial student. Physically, the tutorial map is stored as a text file in Lisp syntax; Wtutor reads in the map at the student’s or author’s request.

While the tutorial map eliminates the filtering problem for the student, it does not solve the problem for the tutorial author. The author must still find or create URLs to include in the tutorial; for this task the author can use tools such as the MetaCrawler to find URLs that may be appropriate. The author must still evaluate the candidates to determine fitness for inclusion in the tutorial.

The tutorial map is created online by the author. The tutorial author can add or delete URLs from the tutorial map using Wtutor. The author can either specify a fully qualified URL, or retrieve the URL using Tmosaic and then specify that that URL should be added to the tutorial map. The author also specifies precedence information in the tutorial map. This precedence information is used by Wtutor to determine the sequence in which the URLs and assessment points of the tutorial should be viewed. To make it easier for the tutorial author to establish the precedence relations between the nodes of the tutorial map, a group feature is provided, so that the author can specify groups of URLs and then declare precedence between groups, between groups and individual URLs, and between URLs and groups.

If desired, the author can require that certain URLs be displayed together; for example, a graphic image such as a map could be displayed along with a commentary that describes a historical trade route that can be found on the map. The author can also identify alternative URLs; that is, if URL A and URL B are alternatives, the student would not need to view B if the student had already viewed A.

Wtutor uses the information it receives from Tmosaic to track the student’s progress through the tutorial map. Whenever a URL is retrieved, Tmosaic sends messages to Wtutor specifying that the URL has been retrieved, and asking whether any of the links contained within the URL should be highlighted. Wtutor specifies that a link to a URL should be highlighted when the URL is included in the tutorial map and all precedence requirements for that URL have been met. The tutorial author can specify the highlight color to be used. As the student proceeds through the tutorial, highlighted link displays will always indicate good next choices to visit.

If the student does not have a highlighted link on the currently displayed link, the student can have Wtutor select the next URL to visit. Tmosaic has a Tutor menu item, and one of the selections under the Tutor entry is a Next option. When the student selects the Next option, Wtutor finds a URL that is ready to visit. Wtutor follows a set of rules in searching for the next URL. The overriding rule is that the selected URL must have all it’s precedents completed. Wtutor looks first for a consequent of the current URL; if there are none that are acceptable then consequents of the previous URL visited are checked. If none of these are acceptable, Wtutor looks for URLs within the same group as the current node. Finally, Wtutor looks for any URL within the map whose precedence requirements have all been met.

If all URLs within the tutorial map have been viewed, the student is notified that the tutorial has been completed. The student is given the option of starting a new tutorial.