8.4 Footsteps

http://gorgon.eng.cam.ac.uk/footsteps/ footsteps.html

Nicol, Smeaton, and Slater have developed a guided tour mechanism for the web called Footsteps [Nic95] within the general framework of project INTERACT [Int95]. Footsteps is implemented as a single PERL CGI script, which fetches and displays URLs in the order in which they should appear in the tour. The script then adds navigation buttons to the original web page to navigate within the guided tour (figure I.33). The tour itself is described in the tour file.

Figure I.33 Sample guided tour implemented with Footsteps

Figure I.34 shows a sample tour index, as generated on the fly by the Footsteps script. It allows to directly jump to any URL within the guided tour. Figure I.34 also illustrates what happens if a tour references an invalid URL ("404 Not Found").

Figure I.34 Tour index implemented with Footsteps

Footsteps offers an easy way to build sequential tours, or paths, through the web. Web pages can obviously be reused for different tours. The script does not require any modification to either client or server.

A CGI-based tour mechanism is because of its implementation somewhat clumsy and slow. Initially, CGI offered the only way to add user-defined features to the web. With the advent of Java the web designer has gotten much greater flexibility. We will describe later in chapter 15 our own path mechanism for the web which we have implemented in Java.

While guided tours and paths assist the reader by reducing the complexity of locating information, they also take away flexibility. The tools and techniques presented in the next chapter offer greater flexibility by extending the sequential tour into a hierarchical structure.