Hacktoberfest 2020 'Intro to Knowledge Graph' with Chris Woodward of ArangoDB and reKnowledge. Accompanying video is available here: https://youtu.be/ZZt6xBmltz4

1. Intro to Knowledge Graphs
Chris Woodward

2. 2
Chris Woodward
Developer Relations Engineer
@
● Training
● Development
● Community
● Twitter: @cw00dw0rd
● Slack: Chris.ArangoDB

3. Special Guest reKnowledge
David Costa Faidella

4. Topics
● What is a graph database?
● What is a knowledge graph?
● Knowledge Graph concepts
○ RDF, OWL, TTL, etc.
● Interactive Notebook

5. Graph Database
Simply put, a graph database consists of documents
that
describe relations within data

6. Graph Database
● NoSQL
● Vertex and Connecting Edge Documents
● Directed or Undirected
● Property Labels

7. Graph Database

8. Use Cases
● Recommendation Engines
● Social Networks
● Knowledge Bases
● Machine Learning
● Fraud Detection
● Many more!

9. Use Cases
Graph Course for Freshers:
https://www.arangodb.com/arangodb-graph-
course/

10. Graph Resources
● Graph Course for Freshers:
○ https://www.arangodb.com/arangodb-graph-course/
● What is a Graph Database?
○ https://www.arangodb.com/graph-database/
● ArangoDB Training Center
○ https://www.arangodb.com/arangodb-training-center/
● Getting Started with ArangoDB on Udemy
○ https://www.udemy.com/getting-started-with-arangodb/

11. Knowledge Graphs
● Introduce Concepts
● Review Modelling
● Define Ontology
● Notebook
● reKnowledge example KG!

12. What is a Knowledge Graph?

13. What is a Knowledge Graph?
A basic definition of a knowledge graph is
that it collects the data from multiple
graphs and attempts to implement a
uniform ontology, making the graph data
more accessible.

14. What is a Knowledge Graph?
Wikipedia:
A network of entities, their semantic types,
properties, and relationships.
https://en.wikipedia.org/wiki/Knowledge_graph#Definitions

15. Why Knowledge Graphs?
● Make data more accessible
● Infer new knowledge from data

16. Use Cases
● Natural Language Processing
● Enterprise Knowledge Graphs
● Customer 360
● Compliance

17. Semantic Web
● Linked Data
● Vocabularies
● Inference
● Query
● Vertical Applications
https://www.w3.org/standards/semanticweb/

18. Knowledge Graphs

19. Knowledge Graphs

20. Wikidata vs Wikipedia
● Flexibility requirements
● Knowledge Graph vs Encyclopedia
● Machine Readable vs Human Readable

21. Wikidata vs DBpedia
● Wikidata schema vs OWL derived
schema
● Wikidata model vs RDF based
● DBpedia is Semantic Web focused

22. Modelling
● RDF
● XML
● Triples
● OWL

23. Modelling - RDF
● Resource Description Framework
“The core structure of the abstract syntax is a set
of triples, each consisting of a subject, a
predicate and an object…”
https://www.w3.org/TR/rdf11-concepts/

24. Modelling - SPO
● Subject
● Predicate
● Object

25. RDF Resource
..A resource may be a part of a Web page; e.g. a
specific HTML or XML element within the document
source. A resource may also be a whole collection of
pages; e.g. an entire Web site. A resource may also
be an object that is not directly accessible via the
Web; e.g. a printed book...

26. RDF Resource
● Uniform Resource Identifier (URI): compact
sequence of characters that identifies an
abstract or physical resource
● Internationalized Resource Identifier (IRI):
Generalized URI with better Unicode support
● Uniform Resource Locator (URL): URI/IRI
with additional access information, protocol,
etc.

27. Modelling - Subject
Subject of the expression or statement

28. Modelling - Predicate
The part of a sentence or clause
containing a verb and stating something
about the subject

29. Modelling - Object
The item the subject is acting upon or
relating to.

30. Modelling - End Statement
The period indicates the end of the
statement.

31. Modelling - SPO
● Subject - <http://dbpedia.org/resource/Arthur_Conan_Doyle>
● Predicate - <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
● Object - <http://www.w3.org/2002/07/owl#Thing>

32. Modelling - Serializing
● XML
● Turtle (ttl)
● N-triples (nt)
● N-quads (nq)
● JSON

33. Ontology - W3
...Vocabularies are used to classify the terms
that can be used in a particular application,
characterize possible relationships, and
define possible constraints on using those
terms…
https://www.w3.org/standards/semanticweb/ontolo
gy

34. Ontology - Wikipedia
In computer science and information science,
an ontology encompasses a representation,
formal naming and definition of the
categories, properties and relations between
the concepts, data and entities that
substantiate one, many or all domains of
discourse.

35. OWL
The W3C Web Ontology Language (OWL) is a
Semantic Web language designed to
represent rich and complex knowledge about
things, groups of things, and relations
between things.
https://www.w3.org/OWL/

36. OWL
https://www.w3.org/2002/07/owl#Thing

37. Notebook
https://github.com/cw00dw0rd/intro-to-knowledge-graphs

38. Thank you!