Deriving the AST, an essential element in the wrapper building process, is an error-prone task. In order to verify the operation, we provide a module called Structure Visualizer (StruViz). This component takes a description file as input, and displays the associated tree. In Figure 4 we display part of the structure of Eddie-Bauer’s catalog. Once the structure of the catalog is visualized, it is easy to verify whether it is accurate. An accurate hierarchy is one that preserves the structure of the catalog (including the links).

StruViz is implemented on the top of Graphite, a universal tool for graph visualization developed at University of Toronto.

Figure 4: The Eddie-Bauer structure visualized by StruViz