3 TE RECOGNITIONWE DEFINE A QUESTION FOCUS AS A TYPE OF INFORMA-TION...

3.3 TE recognition

We define a question focus as a type of informa-

tion that a user wants to know. For example, in

In the TE identification phase, pre-defined words,

the question What movies will be shown on TV

phrases, and named entities are identified as slot-

tonight?

, the question focus is a program title, or

filler candidates for appropriate slots, according to

titles. For another example, the question focus is

TE tagging rules. For instance, movie and NBC

a current rainfall in a question San Francisco is

are tagged as Genre and Channel in the sample

raining now, is it raining in Los Angeles too?

.

question Tell me the movie on NBC tonight.

(i.e.

To find the question focus, we define question

movie will be used to fill Genre slot and NBC

focus region, a part of a question that may contain

will be used to fill Channel slot in a semantic

clues for deciding the question focus. The ques-

frame). The hand-crafted TE tagging rules basi-

tion focus region is identified with a set of simple

cally consider the surface form and the concept

rules which consider the characteristic of the Ko-

name (derived from domain ontologies) of a target

rean interrogatives. Generally, the question focus

word. The context surrounding the target word or

region has a fixed pattern that is typically used in

word dependency information is also considered

interrogative questions(Akiba et al., 2002). Thus

in some cases. In the example question of Figure

a small number of simple rules is enough to cover