A hierarchical approach to model web query interfaces for web source integration

Abstract

Much data in the Web is hidden behind Web query interfaces. In most cases the only means to "surface" the content of a Web database is by formulating complex queries on such interfaces. Applications such as Deep Web crawling and Web database integration require an automatic usage of these interfaces. Therefore, an important problem to be addressed is the automatic extraction of query interfaces into an appropriate model. We hypothesize the existence of a set of domain-independent "commonsense design rules" that guides the creation of Web query interfaces. These rules transform query interfaces into schema trees. In this paper we describe a Web query interface extraction algorithm, which combines HTML tokens and the geometric layout of these tokens within a Web page. Tokens are classified into several classes out of which the most significant ones are text tokens and field tokens. A tree structure is derived for text tokens using their geometric layout. Another tree structure is derived for the field tokens. The hierarchical representation of a query interface is obtained by iteratively merging these two trees. Thus, we convert the extraction problem into an integration problem. Our experiments show the promise of our algorithm: it outperforms the previous approaches on extracting query interfaces on about 6.5% in accuracy as evaluated over three corpora with more than 500 Deep Web interfaces from 15 different domains.

Automatically Mapping and Integrating Multiple Data Entry Forms into a Database

“…In particular, Wu et al [27] and Dragut et al [12] model a search interface as a hierarchical structure call schema tree. To extract schema trees, Dragut et al in [12] develop a rule-based approach exploiting Web browser rendering. We develop a modelbased machine learning technique for extracting a tree structure from a data entry form.…”

“…Example form elements include text label, text box, radio buttons, select list, and check boxes. The underlying relationships among the elements are naturally captured by a tree structure [27,12]. Here, we formally define a form tree as follows.…”

How the Minotaur Turned into Ariadne: Ontologies in Web Data Extraction

“…Form understanding, as the gate-way process in automated web data extraction, has been addressed in the context of deep web search [1,2,3,4], web querying [5,6], and web extraction [7]. These approaches focus on observing commonalities of general web forms and exploiting the arising patterns in specifically tailored algorithms and heuristics.…”

Deep web integration with VisQI

“…First, query interfaces are extracted from relevant Web pages [4]. Second, they are clustered on application domains [1].…”