Fabian M. Suchanek
Source Selection and Preparation
Extractive Entity Typing
The weaknesses of NERC
Named Entity Extraction and Classification (NERC) classifies named entities
into predefined classes.
Traditional systems work with 5-20 classes,
modern systems with up to 10,000 classes.
However, we are inherently limited by the classes that were known
at training time.
Bertrand Russel lived in the UK.
<PER> <PER> <LOC>
Def: Entity Typing
(Extractive) Entity Typing
is the task of extracting named entities and their
class from text documents.
Hypatia of Alexandria was a philosopher,
astronomer, and mathematician.
[Jules Maurice Gaspard]
<Hypatia, type, philosopher>
<Hypatia, type, astronomer>
<Hypatia, type, mathematician>
Different from NERC, the classes are mentioned verbatim in the text.
Entity Typing: Example
Hypatia established herself as a leading mathematician
in the city of Alexandria/Egypt. Historian Socrates Scho‐
lasticus, a Greek Christian, wrote that her attainments in
literature and science by far surpassed all the philoso‐
phers of the Eastern Roman Empire. As a life‐long pagan,
Hypatia was brutally murdered by a mob of Christians
under the lead of a lector named Peter. Her role as one
of the world’s first female academics, murdered with
horrific cruelty, has made her a symbol of female
empowerment, tolerance, and Enlightenment values.