Research Article

Refining Automatically Extracted Knowledge Bases Using Crowdsourcing

Box 2

Sample semantic constraints in NELL.
(a) Ontological Constrains
 Domain(ceoof, ceo)
 Ran(ceoof, company)
 Sub(ceo, person)
 RSub(ceoof, topmemberoforganization)
 RSub(topmemberoforganization, worksfor)
 RSub(topmemberoforganization, personleadsorganization)
 Rsub(worksfor, personbelongstoorganization)
 RMut(topmemberoforganization, organizationleadbyperson)
(b) Candidate Facts
Rel(, , ceoof)
Cat(, ceo)
Cat(, company)
Rel(, , topmemberoforganization)
Rel(, , organizationleadbyperson)
Rel(, , worksfor)
Cat(, person)
Rel(, , personbelongstoorganization)
(c) Ground Rules