Introduction
From UMBELwiki
UMBEL (Upper Mapping and Binding Exchange Layer) is a lightweight ontology or structure for relating Web content and data to a standard set of subject concepts. Its purpose is to provide a fixed set of reference points in a global knowledge space. These subject concepts have defined relationships between them, and can act as binding or attachment points for any Web content or data.
Connecting to the UMBEL structure thus provides context to Web data. In this manner, Web data can be linked, made interoperable, and more easily navigated and discovered.
Depending on purpose or role, UMBEL can be described as:
- A road map — an interconnected map of 21,000 subject concepts that provide the reference signposts to place information in context and in relation to other data
- A backbone — 21,000 solidly connected nodes to which the real things of the world ("named entities") and other external ontologies and distributed datasets can be bound or attached
- Middleware — an API between the integral OpenCyc knowledge base from which UMBEL's subject concepts and relationships are derived and external Web data and structures
- An infocline — a transition layer between the closed world of Cyc with its strong inferencing and logic capabilities and the open world of Web data and RDF
- Linked Data in context — fully exposed as Linked Data to provide a conceptual graph for other Linked Data to relate and interconnect, and
- A lightweight ontology — a fully specified RDF vocabulary based mostly on SKOS but with OWL and other RDFS aspects for complete interoperability with the Semantic Web.
UMBEL is like a map of an interstate highway system, a set of roadsigns to help find related content and a way of getting from one big place to another. Once in the right vicinity, other maps (or ontologies), more akin to detailed street maps, are then necessary to get to specific locations or street addresses.
By definition, these more fine-grained maps are beyond UMBEL's scope. But UMBEL can help provide the context for placing such detailed maps in relation to one another and in relation to the Big Picture of what related content is about.
These subject concepts also provide the mapping points for the many, many (indeed, millions of) named entities that are the notable instances of these subject concepts. Examples might include the names of specific physicists, cities in a country, or a listing of financial stock exchanges. UMBEL mappings enable us to link a given named entity to the various subject classes of which it is a member.
And, because of relationships amongst subject concepts in the backbone, we can also relate that entity to other related entities and concepts. The UMBEL backbone traces the major pathways through the content graph of the Web. The UMBEL backbone graph can be visualized at large or small scale. The UMBEL subject concept graph can also be applied to any form of Linked Data, be it public, open, proprietary or enterprise.
UMBEL terminology contrasts its subject concepts with abstract concepts and with named entities. We define subject concepts as a special kind of concept: namely, ones that are concrete, subject-related and non-abstract. Named entities are the real things or instances in the world that are themselves natural and notable instances (members) of subject concepts (classes).
UMBEL's purpose is pragmatic and emphasizes representational concepts over unattainable precision or exactitude, consistent with the open world character of the semantic Web. Besides the central importance of OpenCyc, UMBEL also has combined some of the best aspects of Wikipedia, DBpedia, WordNet and YAGO.
The initial UMBEL vocabulary defines some important new predicates and leverages existing semantic Web standards. The ontology is provided as Linked Data with Web services access and SPARQL endpoints. Besides its 21,000 subject concepts and relationships distilled from OpenCyc, a further 1.5 million named entities is mapped to that structure. The system is easily extensible.
UMBEL is provided as open source under the XXX license; the complete ontology with all subject concepts, definitions, terms and relationships can be freely downloaded. Five volumes of technical documentation are also available.
Development of UMBEL and the hosting of its Web services is provided by Zitgist LLC with support from OpenLink Software.
