<s>
In	O
information	B-General_Concept
extraction	I-General_Concept
,	O
a	O
named	B-General_Concept
entity	I-General_Concept
is	O
a	O
real-world	O
object	O
,	O
such	O
as	O
a	O
person	O
,	O
location	O
,	O
organization	O
,	O
product	O
,	O
etc.	O
,	O
that	O
can	O
be	O
denoted	O
with	O
a	O
proper	O
name	O
.	O
</s>
<s>
Examples	O
of	O
named	B-General_Concept
entities	I-General_Concept
include	O
Barack	O
Obama	O
,	O
New	O
York	O
City	O
,	O
Volkswagen	O
Golf	O
,	O
or	O
anything	O
else	O
that	O
can	O
be	O
named	O
.	O
</s>
<s>
Named	B-General_Concept
entities	I-General_Concept
can	O
simply	O
be	O
viewed	O
as	O
entity	O
instances	O
(	O
e.g.	O
,	O
New	O
York	O
City	O
is	O
an	O
instance	O
of	O
a	O
city	O
)	O
.	O
</s>
<s>
From	O
a	O
historical	O
perspective	O
,	O
the	O
term	O
Named	B-General_Concept
Entity	I-General_Concept
was	O
coined	O
during	O
the	O
MUC-6	B-General_Concept
evaluation	I-General_Concept
campaign	I-General_Concept
and	O
contained	O
ENAMEX	B-General_Concept
(	O
entity	O
name	O
expressions	O
e.g.	O
</s>
<s>
In	O
the	O
expression	O
"	O
Named	B-General_Concept
Entity	I-General_Concept
"	O
,	O
the	O
word	O
"	O
Named	O
"	O
aims	O
to	O
restrict	O
the	O
possible	O
set	O
of	O
entities	O
to	O
only	O
those	O
for	O
which	O
one	O
or	O
many	O
rigid	O
designators	O
stands	O
for	O
the	O
referent	O
.	O
</s>
<s>
Both	O
"	O
Biden	O
"	O
and	O
the	O
"	O
United	O
States	O
"	O
are	O
named	B-General_Concept
entities	I-General_Concept
since	O
they	O
refer	O
to	O
specific	O
objects	O
(	O
Joe	O
Biden	O
and	O
United	O
States	O
)	O
.	O
</s>
<s>
However	O
,	O
"	O
president	O
"	O
is	O
not	O
a	O
named	B-General_Concept
entity	I-General_Concept
since	O
it	O
can	O
be	O
used	O
to	O
refer	O
to	O
many	O
different	O
objects	O
in	O
different	O
worlds	O
(	O
in	O
different	O
presidential	O
periods	O
referring	O
to	O
different	O
persons	O
,	O
or	O
even	O
in	O
different	O
countries	O
or	O
organizations	O
referring	O
to	O
different	O
people	O
)	O
.	O
</s>
<s>
There	O
is	O
also	O
a	O
general	O
agreement	O
in	O
the	O
Named	B-General_Concept
Entity	I-General_Concept
Recognition	I-General_Concept
community	O
to	O
consider	O
temporal	O
and	O
numerical	O
expressions	O
as	O
named	B-General_Concept
entities	I-General_Concept
,	O
such	O
as	O
amounts	O
of	O
money	O
and	O
other	O
types	O
of	O
units	O
,	O
which	O
may	O
violate	O
the	O
rigid	O
designator	O
perspective	O
.	O
</s>
<s>
The	O
task	O
of	O
recognizing	O
named	B-General_Concept
entities	I-General_Concept
in	O
text	O
is	O
Named	B-General_Concept
Entity	I-General_Concept
Recognition	I-General_Concept
while	O
the	O
task	O
of	O
determining	O
the	O
identity	O
of	O
the	O
named	B-General_Concept
entities	I-General_Concept
mentioned	O
in	O
text	O
is	O
called	O
Named	B-General_Concept
Entity	I-General_Concept
Disambiguation	I-General_Concept
.	O
</s>
