SECTION 3.3. A BENEFIT, SINCE IT GIVES MORE OPPORTUNITY FOR ENFORC-

5.4 Establishing Term Equivalence

We have extended earlier Constraints-based work

The somewhat surprising condition that emerged

through the method of question inversion. The ap-

from this effort was the need for a much more com-

proach uses our QA system recursively, by taking

plete ability than had previously been recognized for

candidate answers and attempts to validate them

the system to establish the equivalence of two terms.

through asking the inverted questions. The outcome

Redundancy has always played a large role in QA

is a re-ranking of the candidate answers, with the

Lenat, D. 1995. "Cyc: A Large-Scale Investment in

possible insertion of nil (no answer in corpus) as the

Knowledge Infrastructure." Communications of

top answer.

the ACM 38, no. 11.

Miller, G. “WordNet: A Lexical Database for Eng-

While we believe the approach is general, and can

lish”, Communications of the ACM 38(11) pp.

work on any question and arbitrary candidate lists,