Facilitating Complex Web Queries Through Visual User Interfaces and Query Relaxation

The World Wide Web can be viewed as a collection of multimedia documents in the form of HTML pages connected through hyperlinks. We have designed and implemented a Web query system, WebDB, to support more comprehensive database-like query functionalities. WebDB supports queries on not only document level information (e.g. title, URL, keywords) but also intra-document structures (e.g. tables, forms, and images) and inter-document linkage information (e.g. URLs and anchors) To provide higher usability for a system with such functionalities, we have designed a novel visual user interface, WebIFQ (Web In-Frame-Query), to assist users in specifying queries and visualizing query criteria including document metadata, structures, and linkage information. WebIFQ automatically generates corresponding query statements for WebDB. As a result, users are not required to be aware of underlying complex schema design and language syntax. WebDB supports automated query relaxation to include additional terms related by semantic or co-occurrence relationship. Alternatively, WebIFQ can facilitate users to reformulate queries perpetually in an interactive mode.