Footsteps: Trail-blazing the Web

Abstract

The World Wide Web has already been demonstrated to be an excellent mechanism for the distribution of educational resources. However, current browsers do not provide much support for users navigating the Web. This is particularly true in cases where users follow a link from a previously prepared 'trail' and then experience difficulties in returning to the point where they left. This paper describes a guided tour mechanism, known as Footsteps, which has been developed in an attempt to solve this problem.

Keywords

Authoring Environments

Computer Based Training and Teaching

Tools and Browsers

CGI-SCRIPTS

Introduction

The production of good educational simulations is a costly undertaking, typically requiring at least one person-year. To justify the construction of such programs it is necessary to be able to use each simulation in as many circumstances as possible and within courses produced by different teachers. In a similar fashion, the components of the associated courseware should also be as reusable as possible. Although the Web provides a superb basis for the development of distributed educational resources, navigation through the resulting structure can be confusing. Although it is arguable that such free exploration should be encouraged, we feel that the pragmatic constraints often placed upon students requires that additional navigational aids be provided. These constraints are especially obvious where systems are being used to augment traditional laboratory work on science or engineering courses.

The fact that students quite often have specific educational objectives for a particular session can therefore be seen to conflict with the possibilities for open-ended exploration presented by the Web. Novice users often feel lost in the information spaces, unsure of where they are, "there is a risk that they will become disoriented or have trouble finding the information they need" [Nielsen 1990]. Even in a small document which could be read in one hour, "users experienced the 'lost in hyperspace' phenomenon" [Neilson & Lyngbaek 1990].

A simple solution to this problem is to construct courseware modules which are relatively self-contained with few opportunities provided for exploration. This type of courseware has already been used successfully with students at the three universities involved in INTERACT. Unfortunately, this approach can be seen to be somewhat at odds with the general 'spirit' of the Web.

Navigational aids within documents have been observed to be a cause of many navigational problems. Attractive navigation icons are often included within documents, with buttons such as "Forward", "Back" and "Up". These are almost inevitably hard-wired links to specific documents. These types of buttons are, of course, rather difficult to provide in documents (such as glossaries) which will be linked to by many URLs. This problem is compounded by the inconsistencies between the navigational controls provided by browsers and those included within documents. Assuming non-linear navigation through a document, it is almost always the case that the result of selecting a "Back" link in a document will differ from the, apparently equivalent, button on the browser.

To fully exploit the Web as a vehicle for the delivery of courseware a more supportive learning environment is required which can still make use of all the power of the Web whilst still maintaining a level of control over navigation. We must provide a navigational mechanism that allows students to follow interesting links to resources anywhere on the Web whilst providing a simple means of returning to the point where the student left the set of materials which have been designated as being directly associated with the current educational objective.

Guided Tours

Guided tours can help to remove the dependency on navigating through a complex structure of hypertext nodes, and "can be used to introduce new readers to the general concept of a hypertext" [Nielsen 1990]. Shown below is a conceptual diagram of navigating through a set of pages using a guided tour, with added functionality to manage any digression from the tour:

INTERACT has developed a guided tour system for the Web, called Footsteps, which is intended for use with simulation-based courseware. Authors can set a pre-defined path for users to navigate through the courseware, with students being allowed digressions from this pre-defined path whilst being provided with a "Return to tour" button on all documents not included in the tour, regardless of the source of these documents. An information bar is added to each document which contains the current location within the tour and links for following the tour.

Shown below is a typical page from a Footsteps tour, this example is a tutorial document used along-side an external soil mechanics simulation:

The user is free to click on any link on the page, if this takes them to a page outside the tour then this new page will be modified 'on the fly' to include a link back to the most recently accessed tour page. The user is able to travel as far as she wants from the tour with the security of always having available a direct means of returning to the appropriate step in the tour.

An example of what happens if the user digresses from a tour is shown below, in this case the user has selected the help tutorial:

An index button is also supplied on all pages on the tour, this allows users to examine the overall structure of the tour upon which they have embarked. The index page provides links to all the pages on the tour. A sample index page is shown below:

Implementation

Footsteps is implemented as a single perl CGI script [Wall & Schwartz 1990], [McCool 1993], using libwww-perl [Fielding 1994]. The script reads a tour file, which specifies the URLs in the order they are to appear in the tour. Additional configuration parameters can also be specified within the this file. An example tour file is shown below:

BUTTON LOCATION 
top 
PREVIOUS ICON 
http://www.eee.strath.ac.uk/images/previous.gif
NEXT ICON
http://www.eee.strath.ac.uk/images/next.gif
INDEX ICON
http://www.eee.strath.ac.uk/images/index.gif
USE DESCRIPTION
no
START TOUR
http://www.eee.strath.ac.uk/
http://www.eee.strath.ac.uk/~nicol/david.html
http://www.cee.hw.ac.uk/
http://www.cee.hw.ac.uk/~calum/calum.html
END TOUR

• Adds the information bar, with the current index in the tour and a set of navigation buttons;

• Parses the HTML and makes all link anchors and inline objects absolute references;

• Parses the HTML looking for Anchor tags and redirects all anchors back to the footsteps script with the original URL from the anchor as a parameter to the script;

• Hidden form fields are used within the HTML returned to the client to store the current page number between documents. This means that no state information needs to be stored by the W3 server.

The figure below shows how the script sits between the user's client and the servers which provides the documents on the tour:

Navigation Tool Configuration

• The navigation bar can be at the top or bottom of the page;

• A description field can be included alongside the "Next" and "Previous" icons, describing the pages to which these buttons link;

• The images to use as the icons can be specified as URLs.

Advantages

The advantages of Footsteps are listed below:

• Users are allowed to follow a linear path through a large information space, but they are still allowed to digress from the tour to explore other information sources with the ability to easily return back to the tour;

• Tour overviews, in the form of the index document, provide extra navigational facilities;

• By using Footsteps, documents can remain reusable resources and be used in more than one tour as tour information is held independently of these resources;

• Using such a script, implementing meta-information such as glossaries is simplified;

• Any document on the Web can be included in a tour;

• The Footsteps script can be used by a client anywhere on the web, therefore the user does not have to be using the same local file system as the Footsteps script.

• The script does not require any modification to either the server or the client.

Disadvantages

• The whole concept of guided tours actually defeats the beauty of hypertext, in that it brings back an emphasis on linear "page turning" rather than the free exploration of large information spaces.

• Twice the network traffic is created for the main text as all but inlined objects are retrieved in a two-stage process.

• Construction of the index document requires the retrieval of all pages in the tour, in order to extract their <TITLE>...</TITLE> fields. This can take a considerable amount of time and may be wasteful if these pages are never visited.

Experience

The script has also been used for providing tours from home pages, such as the Project INTERACT Home Page [Project INTERACT].

Future Developments

At the moment the index overview facility is comprised of a list of pages on the tour, with the description of the page taken from the <TITLE>...</TITLE> field of each document. We would like to develop this facility to include an optional graphical overview map of the tour. The script is also being extended to allow an extra description field to specified in the tour file, and if present this will be used in the index, rather than having to retrieve the whole document just to retrieve this information.

Summary

The latest version of the script is available at:

http://www.eee.strath.ac.uk/~nicol/footsteps/footsteps.html

References

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World Wide Web Initiative. WWW Home Page: http://info.cern.ch/hypertext/WWW/TheProject.html

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libwww-perl, http://www.ics.uci.edu/WebSoft/libwww-perl/

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Extending hypertext for learning: An investigation of access and guidance tools. in Sutcliffe, A. and Macaulay, L. (Eds.): People and Computers V, Cambridge University Press, 293-304

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The Common Gateway Interface. http://hoohoo.ncsa.uiuc.edu/cgi/

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Hypertext and Hypermedia. Academic Press Ltd.

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Two field studies of hypermedia usability. in McAleese, R. and Green, C. (Eds.) Hypertext: State of the Art, Ablex, 64-72.

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The Interact Communication Facility. Proceedings of the First International Conference on the World-Wide Web, CERN Geneva, Switzerland. http://neptune.cee.hw.ac.uk/~afs/www94/www94.html

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Integrating Simulations and W3 Courseware. Proceedings of the Second International Conference on the World-Wide Web, Chicago. http://www.ncsa.uiuc.edu/SDG/IT94/Proceedings/Educ/smeaton/ise_www/ise_www94.html

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The Authors

David Nicol

The author is currently continuing requirements capture and design of educational W3 authoring support tools.

Calum Smeaton

He has recently set up a W3 consultancy company called Orbital Technologies with fellow author Alan Slater.

Alan Falconer Slater

Alan Falconer Slater is a Research Associate in the Department of Computing and Electrical Engineering at Edinburgh's Heriot-Watt University. He is currently employed on the SERC/DTI MOBIT project which is developing industrial Intelligent Training Systems in collaboration with a number of industrial partners. Alan has also worked on a number of large European projects, funded under the CECÆs ESPRIT programme, investigating model-based diagnosis and ITSs.

During work on the INTERACT TLTP project, which aimed to produce an environment for delivering educational simulations, he became interested in hypermedia tools and the W3. He is currently in the final stages of preparing a PhD thesis which is based on his work in the field of ITS systems. This thesis identifies a generic architecture for intelligent agents which is used to provide the basis for realising the two main modules of an ITS system: the domain expert and the tutor.

As part of the MOBIT project he is examining the possibility of delivering computer-based training material via W3 tools, the training domains for MOBIT being control of a nuclear power plant (with Scottish Nuclear) and the manufacture of computer systems (with Digital Equipment Scotland Limited).