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30/03/2014, 22:20
... and
“where.”
The
Do-specialist
replaces
the
predicate
DO
(from
the
verb
“do”)
with
a
more
specific
verb
chosen
from
those
acquired
for
a
domain.
Although
“do”
does
not
appear
as
the
main
verb
very
often
in
the
database
query
task
,
the
translators
deduce
its
implied
presence
in
some
queries—for
instance
in
such
comparative
questions
as
“What
countries
cover
more
area
than
Peru
Ldoes~?”.
The
comparative
specialist
examines
the
two
arguments
of
a
comparison
to
determine
whether
the
comparison
to
be
made
is
between
two
attribute
values
(e.g.,
Jack’s
height
and
seven
feet)
or
between
an
entity
and
some
value
(e.g.,
Jack
and
seven
feet).
In
the
latter
case,
TEAM
tries
to
identify
the
appropriate
attribute
of
the
entity
(e.g.,
Jack’s
height).
2.3.4
Database
Schema
The
translation
from
logical
form
to
SODA
query
requires
knowing
the
exact
structure
of
the
target
database
and
the
manner
in
which
the
predicates
appearing
in
the
logical
form
are
associated
with
the
relations
in
the
database.
This
information
is
provided
by
the
database
schema,
which
includes
the
following
information8:
•
Definition
of
sorts
in
terms
of
database
relations
(subject)
or
fields
(and
field
value
for
sorts
derived
from
feature
fields).
8The
schema
translator
also
uses
certain
information
in
the
conceptual
schema,
including
taxonomic
information
in
the
sort
hierarchy
and
delineation
information
associated
with
nonsort
predicates.
—
18
—
Figure
5:
Acquiring
the
Virtual
Relations
PKCONT
and
HEMIC
window
for
questions
and
answers.
When
the
DBE
uses
the
mouse
to
select
one
of
the
items
from
the
three
menus,
a
set
of
questions
appears
in
the
question-answering
area
at
the
bottom
of
the
display,
to
which
he
can
then
respond.
One
of
the
general
principles
of
acquisition
is
evident
from
this
display,
namely,
that
the
acqui
sition
is
centered
upon
the
relations
and
fields
in
the
database,
because
this
is
the
information
most
familiar
to
the
DBE.
The
answers
to
each
question
can
affect
the
lexicon,
the
conceptual
schema,
and
the
database
schema.
The
DBE
need
not
be
aware
of
exactly
why
TEAM
poses
the
questions
it
does—all
he
has
to
do
is
answer
them
correctly.
Even
the
entries
displayed
in
the
word
menu
owe
their
presence
to
questions
about
the
database.
The
DBE
volunteers
entries
to
this
menu
only
in
the
case
of
verb
acquisition,
to
supply
an
adjective
corresponding
to
some
noun
already
in
TEAM’s
lexicon,
or
to
enter
a
synonym
for
some
lexicon-resident
word.
The
DBE
is
assumed
not
to
have
any
knowledge
of
formal
linguistics
or
of
natural-language
processing
methods.
He
is
assumed,
however,
to
know
some
general
facts
about
English—for
example,
what
proper
nouns,
verbs,
plurals,
and
tense
are,
but
nothing
more
detailed
than
that.
If
more
sophisticated
linguistic
information
is
required,
as
in
the
case
of
verb
acquisition,
TEAM
proceeds
by
asking
questions
about
sample
sentences,
allowing
the
DBE
to
rely
on
his
intuition
as
a
native
speaker,
and
extracting
the
information
it
needs
from
his
responses.
Virtual
relations
are
specified
iconically.
The
left
side
of
Figure
5
shows
the
acquisi
tion
of
a
virtual
relation
that
identifies
the
continent
(PKCONT-CONTINENT,
derived
from
WORLDC-CONTINENT)
of
a
peak
(PKCONT-NAME,
from
PEAK-NAME)
by
performing
a
database
join
on
the
PEAK-COUNTRY
and
WORLDC-CONTINENT
fields.
Similarly,
the
right
side
of
Figure
5
shows
the
acquisition
of
the
virtual
relation
that
encodes
the
hemisphere
(HEMIC-HEMI)
of
a
country
(HEMIC.NAME)
by
joining
on
the
WORLDC-CONTINENT
and
CONT-NAME
fields.
If
he
wishes,
the
DBE
can
change
previous
answers.
Incremental
updates
are
possible
because
most
of
the
methods
for
updating
the
various
TEAM
structures
(lexicon,
schemata)
were
devised
to
undo
the
effects
of
previous
answers
before
the
effects
of
new
answers
could
be
asserted.
Help
information
is
always
available
to
assist
the
DBE
when
he
is
unsure
how
to
answer
a
question.
Selecting
the
question
text
with
the
mouse
produces
a
more
elaborate
description
of
the
information
TEAM
is
trying
to
elicit,
usually
accompanied
by
pertinent
examples.
Finally,
the
acquisition
component
keeps
track
of
what
information
remains
to
be
supplied
before
TEAM
has
the
minimum
it
needs
to
handle
queries.
The
DBE
does
not
have
to
determine
himself
how
much
information
is
sufficient;
all
he
has
to
do
is
to
perceive
that
no
acquisition
window
indicates
remaining
unanswered
questions.
Of
course,
the
DBE
can
always
provide
information
beyond
the
minimum—for
example,
by
supplying
additional
verbs,
derived
adjectives,
or
synonyms.
—
20
—