HALE – The HUMBOLDT Alignment Editor

Status: Stable, active development

The mapping of elements such as Feature Types and Attributes of one conceptual schema (e.g. GML Application Schemas, Database Schemas or UML models) to another is a cornerstone of data harmonisation. The HUMBOLDT Alignment Editor (HALE) is a tool for defining and evaluating conceptual schema mappings. HALE allows domain experts to create logically and semantically consistent mappings and to transform geodata based on these mappings. Furthermore, a major focus is put on the documentation of the schema transformation process and its impacts, e.g. in the form of lineage information attached to the resultant transformed data.

Watch the HALE Tutorial for getting started!

HALE uses a high-level language for expressing the mappings. They can later be used by the Conceptual Schema Transformer processing component to execute a data transformation, e.g. from a non-harmonised data source to a INSPIRE-compliant data set.

To make this complex process more accessible to domain experts and to increase the quality of the transformations, HALE allows working with sample geodata (instances) for visualization and validation. Furthermore, a sophisticated task-based system as it is often used in programming supports users in the creation of a mapping.

The value that HALE provides to data custodians, i.e. maintainers of geographic datasets, is manifold:

• HALE provides a unique declarative approach to making interactive schema mapping a less daunting task;
• HALE is based on a powerful conceptual-level mapping paradigm that makes mappings easier to understand and to maintain;
• HALE makes use of both the information in different conceptual schemas and of geographic instances to ensure high-quality mappings;
• HALE provides a rich, textual and graphical interface specifically adopted for GI Experts;
• HALE gives instant feedback about the progress of mapping data from one schema to another, enabling throughout understanding of the transformation process;
• HALE enables collaborative creation of mappings;
• With HALE, users can furthermore document known limitations of the mapping they are creating in the form of a unique Mismatch Description Language.

HALE is in active use. Since the release of the 1.0 version, it has been downloaded almost 5.000 times. Both research and commercial projects employ HALE.

Download HALE at http://www.esdi-community.eu/projects/hale/files.
Find the HALE Documentation online in the HALE Wiki.