2.4 KINDS OF CONSTRAINT NETWORK THEREFORE WE COLLECTED ALL OF THE “C...
3.2.4 Kinds of constraint network
Therefore we collected all of the “creative” people
There are an unlimited number of possible con-
in the TREC9 question set, and divided them up into
straint networks that can be constructed. We have
classes by profession, so we had, for example, male
experimented with the following:
singers Bob Marley, Ray Charles, Billy Joel and
Timelines. People and even artifacts have life-
Alice Cooper; poets William Wordsworth and
cycles. The examples in this paper exploit these.
Langston Hughes; painters Picasso, Jackson Pollock
1
Painting is only an example of an activity in these constraints.2
This set did not contain definition questions, which, by our Any other achievement that is usually associated with adulthood inspection, lend themselves readily to reciprocation. can be used.What year did X have W
i
?
and Vincent Van Gogh, etc. – twelve such groupings
Who had W
i
?
in all. For each set, we entered the individuals in the
“Google Sets” interface
The top 5 answers to each of these are returned,
(https://traloihay.net), which finds “similar”
again as long as they pass a confidence threshold.
entities to the ones entered. For example, from our
We added a sixth answer “NIL” to each of the date
set of male singers it found: Elton John, Sting, Garth
sets, with a confidence equal to the rejection thresh-
Brooks, James Taylor, Phil Collins, Melissa
old. (NIL is the code used in TREC ever since
Etheridge, Alanis Morissette, Annie Lennox, Jack-
TREC10 to indicate the assertion that there is no
son Browne, Bryan Adams, Frank Sinatra and Whit-
answer in the corpus.) We used a two stage con-
ney Houston.
straint-satisfaction process:
Altogether, we gathered 276 names of creative
Stage 1: For each work W
i