The Web is undoubtedly the largest and most diverse repository of data, but it was not designed to offer the capabilities of traditional data base management systems – which is unfortunate. In a true data federation, all types of data sources, such as relational databases and semi-structured Web sites, could be used together. IBM WebSphere uses the “request-reply-compensate” protocol to communi...

Information extraction from Web sites is nowadays a relevant problem, usually performed by software modules called wrappers. A key requirement is that the wrapper generation process should be automated to the largest extent, in order to allow for large-scale extraction tasks even in presence of changes in the underlying sites. So far, however, only semi-automatic proposals have appeared in the ...

Wrapping is an established technique for API migration: the use of a given API within the system under migration is replaced by the use of a wrapper-based re-implementation of said API while using a different (preferred) API underneath. Except for some special cases, wrapper development is a craft. In particular, the compliance of a wrapper with the original API is hard to assess and guidance o...

| Integrating a large number of Web information sources may signiicantly increase the utility of the WorldWide Web. A promising solution to the integration is through the use of a Web Information mediator that provides seamless, transparent access for the clients. Information mediators need wrappers to access a Web source as a structured database, but building wrappers by hand is impractical. P...

Web datasources usually allow a restricted access (through CGI calls) and their output consists of generated HTML documents. Unfortunately , in many cases the data they provide happen to be available only on the Web. In this paper, we describe a system based on a Web wrapper combined with an object multidatabase system that enables the user to query Web datasources as well as other datasources ...

This work presents a hybrid wrapper/filter algorithm for feature subset selection that can use a combination of several quality criteria measures to rank the set of features of a dataset. These ranked features are used to prune the search space of subsets of possible features such that the number of times the wrapper executes the learning algorithm for a dataset with M features is reduced to O(...

Recent work in machine learning for information extraction has focused on two distinct sub-problems: the conventional problem of filling template slots from natural language text, and the problem of wrapper induction, learning simple extraction procedures (“wrappers”) for highly structured text such as Web pages. For suitable regular domains, existing wrapper induction algorithms can efficientl...

Adequate selection of features may improve accuracy and efficiency of classifier methods. There are two main approaches for feature selection: wrapper methods, in which the features are selected using the classifier, and filter methods, in which the selection of features is independent of the classifier used. Although the wrapper approach may obtain better performances, it requires greater comp...

Wrapper induction techniques traditionally focus on learning wrappers based on examples from one class of Web pages, i.e. from Web pages that are all similar in structure and content. Thereby, traditional wrapper induction targets the understanding of Web pages generated from a database using the same generation template as observed in the example set. Applying such techniques to Web sites gene...