Logic-Based Schema Alignment for Natural History Museum Databases

In natural history museums, knowledge organization systems have gradually been migrated from paper-based catalog ledgers to electronic databases; these databases in turn must be migrated from one platform or software version to another. These migrations are by no means straightforward, particularly when one data schema must be mapped to another-or, when a database has been used in other than-its-intended manner. There are few tools or methods available to support the necessary work of comparing divergent data schemas. Here we present a proof-of-concept in which we compare two versions of a subset of the Specify 6 data model using Euler/X, a logic-based reasoning tool. Specify 6 is a popular natural history museum database system whose data model has undergone several changes over its lifespan. We use Euler/X to produce visualizations (called "possible worlds") of the different ways that two versions of this data model might be mapped to one another. This proof-of-concept lays groundwork for further approaches that could aid data curators in database migration and maintenance work. It also contributes to research on the unique challenges to knowledge organization within natural history museums, and on the applicability of logic-based approaches to database schema migration or crosswalking.