Domain-specific web applications often need to integrate information from schematically heterogeneous sources that share some semantic similarities. These applications often include application widgets—where each widget may address a (potentially small) subset of the local schema. We seek to provide flexible integration where each widget may use its own “global” schema and use its own mapping to each local schema. It is possible for each such “global” schema to be mapped multiple times, in different ways, to a given local schema. Traditional information integration is too rigid to meet these requirements. Here, we define a new integration model that introduces a metamodel of small domain-specific schema fragments—called domain structures—that can be mapped to local schemas. We show how generic, polymorphic widgets can be created by writing queries against domain structures using an extended relational algebra that includes a local type operator to propagate local type names to the domain structures. By bringing the local semantics to the global level we create an integration system with local dominance where important, distinct local schema semantics are available globally.

With the proliferation of digital educational resources comes the requirement to provide educators with tools for collaboration, customization, and reuse of these resources. We describe our repository software built upon the Drupal content management system that allows educators to form curriculum-based online communities to create, share, and adapt educational resources and curricula. Teachers can create curricula from scratch, add to existing curricula, or clone and customize curricula to fit their teaching environment. We also show how our system can help educators see the usage contexts of their materials. The software is demonstrated in the STEMRobotics middle and high school robotics curricula repository and the MSScience middle school standards-based curriculum collaboration site.

Applications typically have some local understanding of a database schema, a virtual database that may differ significantly from the actual schema of the data where it is stored. Application engineers often support a virtual database using custom-built middleware because the available solutions, including updatable views, are unable to express necessary capabilities. We propose an alternative means of mapping a virtual database to a physical database that guarantees they remain synchronized under data or schema updates against the virtual schema. One constructs a mapping by composing channel transformations (CTs) that encapsulate atomic transformations --- including complex transformations such as pivoting --- with known updatability properties. Applications, query interfaces, and any other services can behave as if the virtual database is the implemented schema. We describe how CTs translate queries, DML, and DDL, and the properties that are necessary for such translation to be correct. We describe two example CTs in detail, and evaluate an implementation of channels for completeness and performance.