Knowledge Representation
as part of SD213 (Cognitive Approach to NLP)
CC-BY Fabian Suchanek
What you have seen so far
“Elvis Presley was the greatest rock’n roll singer of all times.”
NP
VP
NP
Parsing
Verb
Adj
Subject: Elvis Presley
Verb: is
Object: singer
What you will see in this lecture
“Elvis Presley was the greatest rock’n roll singer of all times.”
Parsing
Subject: Elvis Presley
Verb: is
Object: singer
Information
extraction
singer
type
NP
VP
NP
Verb
Adj
Knowledge
representation
singer
type
marriedTo
actor
type
person
subclass
subclass
What you will see in this lecture
Knowledge
Base
A
knowledge base
(KB) is a machine‐readable collection of knowledge
about the real world, which typically has to fulfill semantic constraints.
A KB often takes the form of a graph.
Knowledge Base
5
Constraints:
• only people can be married
• every singer is also a person
• ...
singer
type
marriedTo
actor
type
person
subclass
subclass
Knowledge
Base
6
Example: YAGO KB about Elvis
Try it out!
What you will see in this lecture
• Why information extraction is useful (
slides
)
• How information extraction works (
slides
)
• How knowledge is represented (
slides
)
• How to extract facts (
slides
)
• Knowledge bases in research (
slides
)
singer
type
marriedTo
actor
type
person
subclass
subclass