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UMBEL contains about 21,000 subject concepts arranged in relation to one another as a concept graph. These subject concepts are the binding points for linking external named entities and external ontologies to the structure. All subject concepts and their relationships are drawn exactly from the OpenCyc version of the Cyc knowledge base, though those systems are each at least ten times bigger and with richer relationships than what is contained in the lightweight UMBEL structure.
You may download the full UMBEL ontology and manipulate and inspect it with a variety of graphing programs. However, for those unwilling to install or learn such software, we present below some representative snapshots of this UMBEL backbone. These images came from the excellent Cytoscape large-graph visualization framework.
So, here is the big graph, with all nodes and edges (blue) displayed. This is just about at the limit of the Cytoscape graphing program:
Through the manipulation of the topological coefficient, which is a relative measure for the extent to which a node shares neighbors with other nodes, we can zoom in on the Top 750 (actually, 759!) node gateways or hubs. There are other ways to evaluate key nodes in a network, but this one fairly nicely approximates the upper structure or hierarchy within the graph:
By tightening the coefficient further, we can get a view of the Top 350 (actually, the top 336). Were the system live and not a captured jpeg, we could zoom in and read the actual node labels.
The real value from a graph structure, of course, is that now we can make selections based on relationships, neighbors and distances for various reasoning, inference or relatedness purposes. This diagram begins by inputting ' saab' as a car concept, and then getting all nodes within two links:
Alternatively, for the same saab car concept, we can get all directly related links (in yellow) and do some pruning of car types to make the subgraph more readable and interesting:
This
ability to manipulate and navigate this large subject backbone at will
provides the benefits and power to the lightweight UMBEL structure.
Because of its common sense grounding, it is an
excellent road map for linking in external named entities and
Web ontologies.
