An extensible constructor tool for the rapid, interactive design of query synthesizers

We describe an extensible constructor tool that helps information experts (e.g., librarians) create specialized query synthesizers for heterogeneous digital-library environments. A query synthesizer provides a graphical user interface in which a digital-library patron can specify a high-level, fielded, multi-source query. Furthermore, a query synthesizer interacts with a query translator and an attribute translator to transform high-level queries into sets of source-specific queries. We discuss how the constructor can facilitate discovery of available attributes (e.g., title), collation of schemas from different sources, selection of input widgets for a synthesizer (e.g., a text box or a drop-down list widget to support input of controlled vocabulary),, and other design aspects. We also describe a prototype constructor we implemented, based on the Stanford InfoBus and metadata architecture.