I am pleased to announce that we released a powerful new version of KBpedia today with e-commerce and logistics capabilities, as well as significant other refinements. The enhancement comes from adding the United Nations Standard Products and Services Code as KBpedia’s seventh core knowledge base. UNSPSC is a comprehensive and logically organized taxonomy for products and services, organized into four levels, with third-party crosswalks to economic and demographic data sources. It is a leading standard for many industrial, e-commerce, and logistics applications.
This was a heavy lift for us. Given the time and effort involved, Fred Giasson, KBpedia’s co-editor, and I decided to also tackle a host of other refinements we had on our plate. All told, we devoted many thousands of person-hours and more than 200 complete builds from scratch to bring this new version to fruition. Proudly I can say that this version finally meets the starting vision we had when we first began KBpedia’s development. It is a solid baseline to build from for all sorts of applications and to make broad outreach for adoption in 2020. Because of the extent of changes in this new version, we have leapfrogged KBpedia’s version numbering from 2.21 to 2.50.
KBpedia is a knowledge graph that provides a computable overlay for interoperating and conducting machine learning across its constituent public knowledge bases of Wikipedia, Wikidata, GeoNames, DBpedia, schema.org, OpenCyc, and, now, UNSPSC. KBpedia now contains more than 58,000 reference concepts and their mappings to these knowledge bases, structured into a logically consistent knowledge graph that may be reasoned over and manipulated. KBpedia acts as a computable scaffolding over these broad knowledge bases with the twin goals of data interoperability and knowledge-based artificial intelligence (KBAI).
KBpedia is built from a expandable set of simple text ‘triples‘ files, specified as tuples of subject-predicate-object (EAVs to some, such as Kingsley Idehen) that enable the entire knowledge graph to be constructed from scratch. This process enables many syntax and logical tests, especially consistency, coherency, and satisfiability, to be invoked at build time. A build may take from one to a few hours on a commodity workstation, depending on the tests. The build process outputs validated ontology (knowledge graph) files in the standard W3C OWL 2 semantic language and mappings to individual instances in the contributing knowledge bases.
As Fred notes, we continue to streamline and improve our build procedures. Major changes like what we have just gone through, be it adding a main source like UNSPSC or swapping out or adding a new SuperType (or typology), often require multiple build iterations to pass the system’s consistency and satisfiability checks. We need these build processes to be as easy and efficient as possible, which also was a focus of our latest efforts. One of our next major objectives is to release KBpedia’s build and maintenance codes, perhaps including a Python option.
Incorporation of UNSPSC
Though UNSPSC is consistent with KBpedia’s existing three-sector economic model (raw products, manufactured products, services), adding it did require structural changes throughout the system. With more than 150,000 listed products and services in UNSPSC, incorporating it needed to balance with KBpedia’s existing generality and scope. The approach was to include 100% of the top three levels of UNSPSC — segments, families, and classes — plus more common and expected product and service ‘commodities’ in its fourth level. This design maintains balance while providing a framework to tie-in any remaining UNSPSC commodities of interest to specific domains or industries. This approach led to integrating 56 segments, 412 families, 3700+ classes, and 2400+ commodities into KBpedia. Since some 1300 of these additions overlapped with existing KBpedia reference concepts, we checked, consolidated, and reconciled all duplicates.
We fully specified and integrated all added reference concepts (RCs) into the existing KBpedia structure, and then mapped these new RCs to all seven of KBpedia’s core knowledge bases. Through this process, for example, we are able to greatly expand the coverage of UNSPSC items on Wikidata from 1000 or so Q (entity) identifiers to more than 6500. Contributing such mappings back to the community is another effort our KBpedia project will undertake next.
Lastly with respect to UNSPSC, I will be providing a separate article on why we selected it as KBpedia’s products and services template, and how we did the integration and what we found as we did. For now, the quick point is that UNSPSC is well-structured and organized according to the three-sector model of the economy, which matches well with Peirce’s three universal categories underlying our design of KBpedia.
Other Major Refinements
These changes were broad in scope. Effecting them took time and broke open core structures. Opportunities to rebuild the structure in cleaner ways arise when the Tinkertoys get scattered and then re-assembled. Some of the other major refinements the project undertook during the builds necessary to create this version were to:
- Further analyze and refine the disjointedness between KBpedia’s 70 or so typologies. Disjoint assertions are a key mechanism for sub-set selections, various machine learning tasks, querying, and reasoning
- Increase the number of disjointedness assertions 62% over the prior version, resulting in better modularity. (However, note the actual RCs affected by these improvements is lower than this percentage since many were already specified in prior disjoint pools)
- Add 37% more external mappings to the system (DBpedia and UNSPSC, principally)
- Complete 100% of the definitions for RCs across KBpedia
- Greatly expand the
altLabelentries for thousands of RCs
- Improve the naming consistency across RC identifiers
- Further clean the structure to ensure that a given RC is specified only once to its proper parent in an inheritance (subsumption) chain, which removes redundant assertions and improves maintainability, readability, and inference efficiency
- Expand and update the explanations within the demo of the upper KBpedia Knowledge Ontology (KKO) (see
kko-demo.n3). This non-working ontology included in the distro makes it easier to relate the KKO upper structure to the universal categories of Charles Sanders Peirce, which provides the basic organizational framework for KKO and KBpedia, and
- Integrate the mapping properties for core knowledge bases within KBpedia’s formal ontology (as opposed to only offering as separate mapping files); see
kbpedia-reference-concepts-mappings.n3in the distro.
Current Status of the Knowledge Graph
The result of these structural and scope changes was to add about 6,000 new reference concepts to KBpedia, then remove the duplicates, resulting in a total of more than 58,200 RCs in the system. This has increased KBpedia’s size about 9% over the prior release. KBpedia is now structured into about 73 mostly disjoint typologies under the scaffolding of the KKO upper ontology. KBpedia has fully vetted, unique mappings (nearly all one-to-one) to these key sources:
- Wikipedia – 53,323 (including some categories)
- DBpedia – 44,476
- Wikidata – 43,766
- OpenCyc – 31,154
- UNSPSC – 6,553
- schema.org – 842
- DBpedia ontology – 764
- GeoNames – 680
- Extended vocabularies – 249.
The mappings to Wikidata alone link to more than 40 million unique Q instance identifiers. These mappings may be found in the KBpedia distro. Most of the class mapping are
owl:equivalentClass, but a minority may be
isAbout predicates as well.
KBpedia also includes about 5,000 properties, organized into a multi-level hierarchy of attributes, external relations, and representations, most derived from Wikidata and schema.org. Exploiting these properties and sub-properties is also one of the next priorities for KBpedia.
To Learn More
The KBpedia Web site provides a working KBpedia explorer and demo of how the system may be applied to local content for tagging or analysis. KBpedia splits between entities and concepts, on the one hand, and splits in predicates based on attributes, external relations, and pointers or indexes, all informed by Charles Peirce‘s prescient theories of knowledge representation. Mappings to all external sources are provided in the linkages to the external resources file in the KBpedia downloads. (A larger inferred version is also available.) The external sources keep their own record files. KBpedia distributions provide the links. However, you can access these entities through the KBpedia explorer on the project’s Web site (see these entity examples for cameras, cakes, and canyons; clicking on any of the individual entity links will bring up the full instance record. Such reach-throughs are straightforward to construct.) See further the Github site for further downloads.
KBpedia was first released in October 2016 with some open source aspects, and was made fully open in 2018. KBpedia is partially sponsored by Cognonto Corporation. All resources are available under the Creative Commons Attribution 4.0 International (CC BY 4.0) license.