Experimental results provide an idea of the amount of effort required to generate a wrapper for a new source. Difficult to automate is the first step where we obtain the structure of a page or sample pages from the source. Structuring step dominates the time and effort needed to build a wrapper for a new source. Generating the parser is then done automatically and defining a mapping function from queries to URLs for sources with multiple pages requires comparatively little effort on part of the user. To provide a quantitative measure of the effectiveness of the heuristics, authors define term called correction steps.
Table also provides the time taken to generate the wrapper for each source.
Table demonstrates the ease with which we built sources for a dozen Internett sites, from both the multiple instance and single instance categories. The results are extremely encouraging. Several sources require almost no or very few correction steps to structure them, thus showing that the heuristics for structuring pages are quite successful. It takes only a few minutes to generate a wrapper for most new sources. Such a toolkit is thus extremely useful as it provides a convenient and quick way to generate wrappers for new sources of information on the web and then integrate them via a mediator.