How many station wagons altogether have stopped?. ONE OF THE THREE ON SCHLUETERSTREET?. Did a station wagon drive off.. YES, ONE ON SCHLUETEBSTREET?. By the way, the light-colored truck
Trang 1CASE ROLE FILLING AS A SIDE EFFECT OF VISUAL SEARCH
H e i n z M a r b u r g e r
R e s e a r c h Unit f o r I n f o r m a t i o n S c i e n c e
and A r t i f i c i a l I n t e l l i g e n c e
U n i v e r s i t y o f Hamburg
M i t t e l w e g 179
D - 2 0 0 0 Hamburg 1 3 , F R Germany
W o l f g a n g W a h l s t e r
FBI0 - A n g e w a n d t e M a t h e m a t l k und i n f o r m a t l k
U n i v e r s i t y of S a a r b r O c k e n
Im S t a d t w a l d
0 - 6 6 0 0 S a a r b r 0 c k e n 11, F.R G e r m a n y
ABSTRACT
T h i s p a p e r a d d r e s s e s the p r o b l e m Of g e n e r a t i n g
c o m m u n i c a t i v e l y a d e q u a t e e x t e n d e d r e s p o n s e s i n t h e
a b s e n c e o f s p e c i f i c k n o w l e d g e c o n c e r n i n g t h e
i n t e n s i o n s o f t h e q u e s t i o n e r We f o r m u l a t e and
j u s t i f y a h e u r i s t i c for the s e l e c t i o n of o p t i o n a l
t a i n e d i n an e x t e n d e d r e s p o n s e I t i s shown t h a t ,
i n a v i s u a l l y p r e s e n t d o m a i n o f d i s c o u r s e , c a s e
r o l e f i l l i n g f o r t h e c o n s t r u c t i o n o f an e x t e n d e d
r e s p o n s e can be r e g a r d e d as a s i d e e f f e c t o f t h e
v i s u a l s e a r c h n e c e s s a r y t o a n s w e r a q u e s t i o n c o n -
t a i n i n g a l o c o m o t i o n v e r b The p a p e r d e s c r i b e s t h e
v a r i o u s r e p r e s e n t a t i o n c o n s t r u c t i o n s used i n t h e
German l a n g u a g e d i a l o g s y s t e m HAM-ANS f o r d e a l i n g
w i t h t h e s e m a n t i c s o f l o c o m o t i o n v e r b s and i l l u s -
t r a t e s t h e i r use i n g e n e r a t i n g e x t e n d e d r e s p o n s e s
I n p a r t i c u l a r , we o u t l i n e t h e s t r u c t u r e o f t h e
g e o m e t r i c a l s c e n e d e s c r i p t i o n , t h e r e p r e s e n t a t i o n
o f e v e n t s i n a l o g i c - o r i e n t e d s e m a n t i c r e p r e s e n t a -
t i o n l a n g u a g e , t h e c a s e - f r a m e l e x i c o n and t h e
r e p r e s e n t a t i o n o f t h e r e f e r e n t i a l s e m a n t i c s b a s e d
d e t a i l e d p r e s e n t a t i o n o f t h e a p p l i c a t i o n o f
o b j e c t - o r i e n t e d p r o g r a m m i n g m e t h o d s f o r c o p i n g
w i t h t h e s e m a n t i c s o f l o c o m o t i o n v e r b s The p r o -
c e s s o f g e n e r a t i n g an e x t e n d e d r e s p o n s e i s i l l u s -
t r a t e d by an e x t e n s i v e l y a n n o t a t e d t r a c e
1 INTRODUCTION
d i r e c t , l i t e r a l r e s p o n s e a l t h o u g h he m u s t assume
t h a t t h e a n s w e r e r i s n o t i n f o r m e d a b o u t w h a t p a r -
t i c u l a r i n f o r m a t i o n he i s s e e k i n g The q u e s t i o n e r
i m p u t e s to a c o o p e r a t i v e d i a l o g u e p a r t n e r the com-
Yes
previous course o f the d i a l o g or the i n t e n t i o n s o f
the q u e s t i o n e r (the unmarked case) an a n s w e r l i k e
( l a ) seems more a p p r o p r i a t e than ( I b ) or ( I c )
( I b ) Yes, w i t h an old school f r i e n d
( I c ) Yes, by plane
OF course, t h e r e are n u m e r o u s d i a l o g s i t u a t l o n s in
w h i c h ( l b ) os" ( l c ) c o u l d be g e n e r a t e d as a commun-
i c a t i v e l y a d e q u a t e r e s p o n s e on t h e b a s i s o f a p a r
t ± c u l a r p a r t n e r m o d e l B u t i t s t i l l m u s t b~ a s k e d
why i n d i a l o g s o f t h e t y p e ' i n f o r m a t i o n , u p p l y '
t h e u n m a r k e d r e s p o n s e t a k e s t h e f o r m ( l a ) ~nd n o t
( l h ) o r ( l c )
computational study o f t h i s problem f o r the domain
R e s e a r c h on HAM ANS Is c u r r e n t l y b e i n g s u p p o r t e d
(8MFT) under c o n t r a c t 081T15038
' l o c o m o t i o n verbs' in d i a l o g s b a s e d on a v i s u a l l y
c o o p e r a t i v e d i a l o 9 s y s t e m s , s i n c e , i n many a p p l i -
c a t i o n s , no e x p l i c i t k n o w l e d g e a b o u t t h e d i a l o g
g o a l s o f t h e q u e s t i o n e r i s a v a i l a b l e a t t h e
o u t s e t I f a , s y s t e m i s n e v e r t h e l e s s e x p e c t e d t o ' o v e r - a n s w e r , i e t o v o l u n t e e r i n f o r m a t i o n t h a t has n o t s p e c i f i c a l l y been r e q u e s t e d , i t m u s t com- mand a s e t o f h e u r i s t i c c r i t e r i a f o r s e l e c t i n g t h e
a d d i t i o n a l i n f o r m a t i o n t h a t i s t o be v e r b a l i z e d [ 1 1 1
I t i s n o t e w o r t h y t h a t t h e t h r e e a d d i t i o n a l p o i n t s
o f i n f o r m a t i o n i n ( l a ) , ( l b ) , ( 1 c ) c o r r e s p o n d t o
f i l l e d d e e p c a s e s l o t s o f t h e v e r b u s e d i n t h e
t i v e l y ) T h i s s u g g e s t s t h a t t h e u n f i l l e d o p t i o n a l
c a s e s l o t s i n t h e q u e s t i o n a r e c a n d i d a t e s f o r
a d d i t i o n a l i n f o r m a t i o n F o r a q u e s t i o n l i k e ( 2 ) ,
i n w h i c h a l l t h e d e e p c a s e s l o t s o f ' b r e a k ' a r e
f i l l e d , o n l y a d i r e c t r e s p o n s e l i k e ( 2 a ) i s t o be
e x p e c t e d as a p o s i t i v e a n s w e r , w h i l e i n ( 3 ) , w h e r e only the o b l i g a t o r y d e e p case s l o t s are f i l l e d , an
e x t e n d e d r e s p o n s e l i k e ( 3 a ) can be e x p e c t e d ( 2 ) D i d y o u b r e a k t h e w i n d o w w i t h y o u r s l i n g s h o t
y e s t e r d a y ? ( 2 a ) Y e s ( 3 ) D i d y o u b r e a k t h e w i n d o w ? ( 3 a ) Y e s , w i t h my s l i n g s h o t
S i n c e not e v e r y o p t i o n a l d e e p c a s e o f a g i v e n verb
u n m a r k e d e x t e n d e d r e s p o n s e ( e g ( l a ) - ( l c ) ) we may
d e f i n e t h e p r o b l e m more p r e c i s e l y by a s k i n g w h i c h
o f t h e d e e p c a s e s l o t s u n s p e c i f i e d i n t h e q u e s t i o n
a r e t o be c h o s e n as t h e u n m a r k e d v a l u e s
F o r o u r d o m a i n Of i n v e s t i g a t i o n ' l o c o m o t i o n v e r b s '
l e t us c o n s i d e r q u e s t i o n s ( 4 ) and ( 5 ) , w h i c h r e f e r
t o a v i s u a l l y p r e s e n t w o r l d o f d i s c o u r s e I n e a c h
c a s e p e r c e p t u a l p r o c e s s e s a r e assumed as a p r e r e -
q u i s i t e f o r t h e a n s w e r
&a) The b u s , on H a r t u n g s t r e e t 4b) The b u s , b e c a u s e t h e d r i v e r s t e p p e d on t h e
b r a k e
5a) Yes, from H a r t u n g s t r e e t onto S c h l u e t e r s t t e e t 5b) Yes, t o g e t h e r w i t h the t a x i cab
p r e d i c t a b l e in c o n t r a s t to the c a u s a t i v e s l o t i n
o p t i o n The choice i s dependent upon the verb con-
u n m a r k e d e x t e n d e d r e s p o n s e s ,
Trang 2FAMILIAR WITH
SCENE BUT
CANNOT SEE IT
PDP-IO
NL DIALOG SYSTEM
H A M
A N S
IMAGE SEQUENCE ANALYSIS SYSTEM NAOS
MORIO
] IL
STREET INTERSECTION
Fig 1: S i t u a t i o n a l c o n t e x t of the d i a l o g
w h i c h c o n t a i n the c o n c e p t s n e c e s s a r y for the p e r -
ceptual verification of the m o t i o n d e s c r l b e d by
the verb
In o r d e r to v e r i f y a s t o p - e v e n t it is n e c e s s a r y to
but not the c a u s e (cf (4b)) For a t u r n - o f f e v e n t
a c h a n g e of d i r e c t i o n b e t w e e n s o u r c e and g o a l m u s t
d e t e r m i n e w h e t h e r o t h e r o b j e c t s m a k e this c h a n g e
of d i r e c t i o n at the same time (cf (Sb))
H e n c e case role f i l l i n g f o r the c o n s t r u c t i o n o f an
e x t e n d e d r e s p o n s e can be r e g a r d e d as a side e f f e c t
of the visual, s e a r c h n e c e s s a r y to a n s w e r the q u e s -
tion
This a l s o a p p e a r s p l a u s i b l e w h e n seen in the l i g h t
a n s w e r e r The q u e s t i o n e r b e l i e v e s that the
a n s w e r e r w i l l fill in the c a s e sluts n e c e s s a r y for
a n s w e r i n g the q u e s t i o n and that it is t h e r e f o r e
q u e s t i o n A d d i t i o n a l l y the q u e s t i o n e r b e l i e v e s
not e x p l i c i t l y r e q u e s t the a d d i t i o n a l i n f o r m a t i o n
e x p e c t a t i o n by a p p l y i n g the h e u r i s t i c f o r m u l a t e d
above
A p r e r e q u i s i t e for the a p p l i c a t i o n of this h e u r i s -
m o s t n a t u r a l l a n g u a g e ( N L ) s y s t e m s since t h e y sim-
ply r e p r e s e n t e v e n t s in t h e d o m a i n or d i s c o u r s e in
fully i n s t a n t ~ a t e d Form u s i n g c a s e frames, e.g as
part of a s e m a n t i c net or frame h i e r a r c h y In con-
( H a m b u r g a p p l i c a t i o n - - o r i e n t e d n a t u r a l l a n g u a g e
f r a m e of each v e r b the s y s t e m i n c l u d e s a represen-
t a t i o n of the r e f e r e n t i a l s e m a n t i c s of p r e d i c a -
p o s s i b l e to ~valuate the ViSual i n p u t data f o r the
movement i n question
The g o a l of this a r t i c l e is to e l u c i d a t e the
r e p r e s e n t a t i o n c o n s t r u c t i o n s for case f r a m e s and
H A M - A N S and to i l l u s t r a t e t h e i r use in g e n e r a t i n g
u n m a r k e d e x t e n d e d r e s p o n s e s
2 A SHORT OVERVIEW OF HA~-ANS
H A M - A N S is a l a r g e German n a t u r a l l a n g u a g e d i a l o g
w h i c h p r e s e n t l y p r o v i d e s a c c e s s to t h r e e d i f f e r e n t
a p p l i c a t i o n c l a s s e s , n a m e l y an e x p e r t s y s t e m ( h o t e l r e s e r v a t i o n s i t u a t i o n ) , a d a t a b a s e s y s t e m
( f i s h e r y d a t a ) and a s c e n e a n a l y s i s s y s t e m
( t r a f f i c s c e n e ) The c o m m u n i c a t i v e s i t u a t i o n s the s y s t e m h a n d l e s are c h a r a c t e r i z e d as follows:
a s s u m e d to h a v e the o v e r a l l g o a l of d e t e r m i n i n g
w h e t h e r the r o o m o f f e r e d m e e t s his r e q u i r e m e n t s
s p e c i f i c d e s i r e s c o n c e r n i n g t h e room as t h e y a r e
r e v e a l e d - u s u a l l y i n d i r e c t l y - in his u t t e r a n c e s
in n a t u r a l l a n g u a g e that p e r m i t the r o o m in q u e s - tion to be p r e s e n t e d in a p a r t i c u l a r l y f a v o r a b l e
l i g h t (e.g the g e n e r a t i o n of t e n d e n t i o u s d e s c r i p - tions u s i n g h e d g e d r e l a t i v e a d j e c t i v e s )
In the d a t a b a s e a p p l i c a t i o n [8] H A M - A N S p r o v i d e s
d a t a b a s e , w h i c h c o n t a i n s d a t a c o l l e c t e d d u r i n g
sets, w h i c h c o n s i s t of c r u i s e d a t a c o n c e r n i n g the
v e s s e l s ' v o y a g e s , k r i l l b i o l o g y d a t a , r e l e v a n t
n e t h a u l s and o c e a n o g r a p h i c d a t a , a r e s t o r e d i n a
r e l a t i o n a l d a t a b a s e (76 r e l a t i o n s 1 1 M B y t e ) w i t h
a PASCAL/R d a t a b a s e m a n a g e m e n t s y s t e m
In the t r a f f i c d o m a i n we p r e s u p p o s e the f o l l o w i n g
Trang 3user, w h o is f a m i l i a r w i t h the scene but c a n n o t
see it f r o m his r e m o t e l o c a t i o n , w i t h i n f o r m a t i o n
s c e n e Is p r o v i d e d by the i m a g e s e q u e n c e a n a l y s i s
semantics o f locomotion verbs ( c f f i g 2)
? How m a n y t r u c k s h a v e y o u s e e n ?
TWO
? W h i c h t r u c k s h a v e g o n e b y ?
A LIGHT-COLORED ONE ON HARTUNGSTREET
? Did a Mellow car and a green station wagon
turn off first?
NO A YELLOW CAR TURNED OFF HARTUNGSTREET
ONTO SCHLUETERSTBEET, BUT THE GREEN STATION
DID NOT TURN OFF F I R S T
? W e r e a y o u n g man a n d an o l d woman w a l k i n g
down Schloeterstreet d u r i n g this time?
YES A N OLD WOMAN A N D A YOUNG MAN
? Did the green station wagon stop on
S c h l u e t e r s t r e e t ?
YES
? How many station wagons altogether have
stopped?
ONE OF THE THREE ON SCHLUETERSTREET
? What did I just ask you?
YOU ASKED: HOW M A N Y STATION WAGONS STOPPED
? Did a station wagon drive off?
YES, ONE ON SCHLUETEBSTREET
? By the way, the light-colored truck: Did
it drive down Schlueterstreet too?
YES
How many cars are there in all?
SIXTEEN
? Is one o f these cars blue 9
Y E S TWO OF THEM ARE KIND OF BLUE
? Did a blue car d r i v e down both s t r e e t s ?
YES, ONE BLUE CAB
So long!
Fig 2: A t r a n s c r i p t o f an a c t u a l d i a l o g
3 REPRESENTATION FORMALISMS FOR THE SEMANTICS OF
LOCOMOTION VERBS
3 , 1 THE GEOMETRICAL SCENE DESCRIPTION
movements t h a t have occurred i n r e a l sequences o f
o b ] e c t s
c o m b i n a t i o n o f a u t o m a t i c a l l y g e n e r a t e d o u t p u t s oF
t h e scene a n a l y s i s p r o c e s s e s ( i n s o f a r as t h i s i s
t a t i o n s
s n a p s h o t s a r e coded in a r e l a t i o n a l f o r m a l i s m ,
d e n o t l n g w h i c h o b j e c t s w e r e o b s e r v e d , t h e shape o f
these o b j e c t s , t h e i r c u r r e n t center o f g r a v i t y and
o b j e c t s and t h e i r d e s c r i p t i o n s are only e n t e r e d if
u n d e r l y i n g c o o r d i n a t e s y s t e m I n c o n t r a s t t o t h e
r e a l TV image s e q u e n c e t h i s r e p r e s e n t a t i o n i s o n l y
2 d i m e n s i o n a l and t h u s p r o v i d e s a b i r d ' s - e y e v i e w
o f t h e s c e n e
3 2 THE REPRESENTATION LANGUAGES SURF AND DEEP
l a n g u a g e s SURF and DEEP a r e t h e c e n t r a l r e p r e s e n -
t a t i o n f o r m a l i s m s used i n HAM-ANS T h e s e l a n g u a g e s
a r e d e s i g n e d t o be d e c l a r a t i v e and e a s i l y e x t e n d -
a b l e SURF i s t h e t a r g e t l a n g u a g e o f t h e a n a l y s i s
c o m p o n e n t s and s o u r c e l a n g u a g e f o r t h e g e n e r a t i o n
u t t e r a n c e s , w h e r e a s DEEP i s b e t t e r s u i t e d f o r t h e
e v a l u a t i o n o f u t t e r a n c e s on t h e b a s i s o f t h e
s y s t e m ' s d o m a i n - s p e c i f i c k n o w l e d g e s o u r c e s
r e p r e s e n t t e r m and p r e d i c a t e s t r u c t u r e s w h i c h
r e s e r v a t i o n s i t u a t i o n For an adequate r e p r e s e n t a -
mented by m e t a - p r e d i c a t e s f o r m a r k i n g deep c a s e s ,
t e n s e and v o i c e a d a p t e d f r o m F i l l m o r e ' s deep c a s e
in ( 7 ) ( 6 ) Did ]ohn f l y to Hamburg?
E-ACT denotes an e x i s t e n t i a l q u a n t i f i c a t i o n o f
are shown i n the annotated example ( c f f i g 8)
d e t a i l e d d e s c r i p t i o n
3 3 THE CASE-FRAME LEXICON
The c a s e f r a m e s f o r v e r b s used i n t h e s y s t e m a r e
i n t h e w o r d l e x i c o n f o r a v e r b c o n t a i n s a p o i n t e r
t o i t s a p p l i c a b l e c a s e f r a m e w h i c h d e s c r i b e s t h e
s e m a n t i c s o f t h a t v e r b i n t e r m s o f c a s e r e l a t i o n s
A c a s e f r a m e i s r e p r e s e n t e d as a c o m b i n a t i o n o f
c a s e i t s name, a m a r k e r , w h e t h e r t h e deep c a s e i s
o b l i g a t o r y ( 0 ) o r o p t i o n a l ( F ) , and t h e s e m a n t i c
r e s t r i c t i o n s w h i c h a r e r e q u i r e d f r o m a s y n t a c t i c
s u b s t r u c t u r e t o f i l l t h e deep c a s e ( o f f i g 3 )
a n a l y s i s phase w i t h o u t p r e d e t e r m i n i n g a s i n g l e
p r o c e s s f o r t h e s e v e r b s d u r i n g t h e e v a l u a t i o n o f
' t o s t o p ' , a s i n g l e case frame, namely t h a t s p e c i -
a p p l i e d during the a n a l y s i s phase
applied during the e v a l u a t i o n o f a complete u t t e r - - ance; The s e l e c t i o n a l r e s t r i c t i o n t h a t , e g , the
v e h i c l e s , and t h e r e f o r e be a p o s s i b l e candidate to
f i l l ~ the agent r o l e o f the verb ' t o s t o p ' , can be
Trang 4set r e l a t i o n in the conceptual semantic net
I n t h e c a s e - f r a m e l e x i c o n t h e c a s e f r a m e s a r e n o t
r e c o r d e d i n t h e f o r m shown i n f i g 3 b u t r a t h e r
a r e r e p r e s e n t e d as c o n s t r u c t o r c a l l s f o r b u i l d i n g
r e s t r i c t i o n s :
o b j e c t i v e :
SOUrce:
l o c a t i v e
( d - l : r o l A - - m a r k e r : F
r e s t r i c t i o n s :
g o a l :
time:
p a t h :
i n s t r u m e h t : ]
Fig 3: Case frames f o r verbs o f type ' t o stop
a c a s e f r a m e a c c o r d i n g t o t h e a c t u a l s y n t a x d e f i n -
m o d i f i c a t i o n s o f SURF a r e i m m e d i a t e l y p r e s e n t i n
t h e case f r a m e s
CONCEPTS
In o b j e c t - o r i e n t e d p r o g r a m m i n g l a n g u a g e s p r o g r a m -
w o r l d o f e n t i t i e s c a l l e d o b j e c t s and o f s p e c i f y i n g
a s e t o f g e n e r i c o p e r a t i o n s t h a t can be p e r f o r m e d
by s e n d i n g and r e c e i v i n g m e s s a g e s E s s e n t i a l l y ,
message t o ar, o b j e c t ( p o s s i b l y t o i t s e l f ) w h i c h i n
t u r n sends a message e t c , u n t i l t h e r e q u i r e d t a s k
i s f u l f i l l e d An i m p o r t a n t b e n e f i t o f t h e o b j e c t -
t i c u l a r l y s i m p l e and l u c i d kind of m o d u l a r i t y
The F l a v o r s y s t e m [ 2 ] [ 1 3 ] i s an i m p l e m e n t a t i o n o f
t h e l a n g u a g e f e a t u r e s t h a t s u p p o r t o b j e c t - o r i e n t e d
p r o g r a m m i n g Two k i n d s o f o b j e c t s e x i s t i n a F l a -
v o r s y s t e m , n a m e l y one c a l l e d f l a v o r and t h e o t h e r
i n s t a n c e of a f l a v o r A flavor r e p r e s e n t s a gen-
t i o n of a ge,~eric o b j e c t It is p o s s i b l e to s e n d
messages to b o t h k i n d s of o b j e c t s F l a v o r s are
o r g a n i z e d in ,, d i r e c t e d g r a p h c a l l e d the f l a v o r
g r a p h • T h e r e is one d e s i g n a t e d flavor, the
v a n i l l a flays, r, w h i c h c o r r e s p o n d s to t h e t h i n g
defined f l a v o r i t s l o c a t i o n in the graph by naming
i n f o r m a t i o n contained in a f l a v o r i s a combination
f l a v o r s and the added i n f o r m a t i o n given by i t s own
This is one d i m e n s i o n of the i n f o r m a t i o n c o n t a i n e d
d e c l a r a t i v e / p r o c e d u r a l d i s t i n c t i o n The d e c l a r a -
of d i f f e r e n t kinds w h e r e a s p r o c e d u r a l k n o w l e d g e is
t h e i r i n d i v i d u a l i n f o r m a t i o n The o t h e r kind - the
c l a s s v a r i a b l e is owned by a flavor, can be
o b j e c t i n t h e f l a v o r s y s t e m H o w e v e r , a f l a v o r i s
o n l y a l l o w e d t o c h a n g e a v a l u e o f a c l a s s v a r i -
a b l e , if it o w n s t h i s v a r i a b l e
M e t h o d s are f u n c t i o n d e f i n i t i o n s t h a t i m p l e m e n t the o p e r a t i o n s d e f i n e d for e a c h flavor The c o m b i -
n a t i o n of m e t h o d s f r o m d i f f e r e n t f l a v o r s is c a l l e d
m i x i n g f l a v o r s
m a i n l y t h r e e d i s t i n g u i s h i n g f e a t u r e s : The 'A k i n d o f ' s l o t i n FRL s e r v e s b o t h f o r
e s t a b l i s h i n g an i n h e r i t a n c e h i e r a r c h y and f o r
c o n n e c t i n g i n s t a n c e s t o s u p e r c l a s s e s , i e no
c l e a r d i s t i n c t i o n i s made b e t w e e n g e n e r i c
f r a m e s and i n s t a n c e s • On t h e o t h e r hand t h e
s u p e r f l a v o r s f o r each f l a v o r , i n s t a n c e s a r e
c r e a t e d by t h e m a k e - i n s t a n c e - m e t h o d
B e c a u s e t h e d i s t i n c t i o n b e t w e e n g e n e r i c
f r a m e s and i n s t a n c e s i s n o t made i n FRL t h e r e
i s a l s o no d i s t i n c t i o n b e t w e e n i n s t a n c e v a r i -
a b l e s and c l a s s v a r i a b l e s • I n t h e F l a v o r s y s -
c l e a r l y d e f i n e d i n t h a t i n s t a n c e v a r i a b l e s can o n l y be m o d i f i e d i n i n s t a n c e s and c l a s s
v a r i a b l e s can o n l y be m o d i f i e d i n f l a v o r s • Frames i n FRL a r e p a s s i v e d a t a s t r u c t u r e s ,
c r e a t e d and m o d i f i e d ; t h e y a r e a u t o n o m o u s ;
r e p r e s e n t i n g common knowledge ( c f [ 2 ] )
knowledge r e p r e s e n t a t i o n language, i t includes the
k n o w l e d g e r e p r e s e n t a t i o n f o r m a l i s m s I n c o n t r a s t
t o a f u l l - f l e d g e d k n o w l e d g e r e p r e s e n t a t i o n
l a n g u a g e t h i s a p p r o a c h r e q u i r e s some a d d i t i o n a l
p r o g r a m m i n g i n t h e b e g i n n i n g , b u t i t a v o i d s any
p e r m a n e n t o v e r h e a d f o r f e a t u r e s w h i c h a r e s u p e r -
f l u o u s f o r t h e t a s k a t hand•
r e p r e s e n t i n g a s p e c i a l i z a t i o n h i e r a r c h y o f m o t i o n
c o n c e p t s ( c f f i g 4 ) The r o o t f l a v o r o f t h i s
h i e r a r c h y i s t h e m o t i o n c o n c e p t HOVE D e s c e n d a n t s
d e c l a r a t i v e and p r o c e d u r a l i n f o r m a t i o n c o n t a i n e d
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in t h e i r p a r e n t s I n s t a n c e v a r i a b l e s c o m p r i s e
i n f o r m a t i o n a b o u t the d e e p c a s e s a s s o c i a t e d w i t h
the m o t i o n c o n c e p t as w e l l as i n f o r m a t i o n n e e d e d
methods
TIME and SPACE are r e s p o n s i b l e f o r temporal and
d e t e r m i n e the t e m p o r a l and s p a t i a l d e s c r i p t i o n of
the a c t u a l scene: the l e n g t h of the s c e n e in time,
the number o f snapshots, the s p a t i a l e x t e n t , e t c
The task o f c h e c k i n g t h e t r u t h value o f the propo-
t h r o u g h m e s s a q e p a s s i n g T h e s e m e s s a g e s i n c l u d e :
( n t ! t h o d S
L e t ' s now c o n , , z d e r t h e e x a m p l e g i v e n i n f i g 5 i n
more d e t a i l '.ince o n l y the AGENT was s p e c i f i e d in
ONLY AGENT S l ~ ' l !ILLED A f t e r determinirlg an
interval ~f c~nsideration this m e t h o d c a l l s
DIRECTION_CHAUGE and FIND_A_GOAL NEQ ~;OURCE
DIRECTION CIIAI;GE i s a s p e c i a l method o f the f l a v o r
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also needed i n t h a t f l a v o r f o r answering q u e s t i o n s
t o H a r t u n g s t r e e t ~ '
agen~'~ t r a j e c t o r y i n the i n t e r v a l o f c o n s i d e r a -
t i o n and checks which o f the o b j e c t s o f the s t a t i c
t e s t o n l y those s t a t i c o b j e c t s are s e l e c t e d t h a t
s o u r c e slot s p e c i f i e d in the c a s e - f r a m e l e x i c o n
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i n s t a n t i a t e d f l a v o r i n s t a n c e , e g TIJRN120 ( c f
f i g ? )
The p r o c e s s i n g o f a u s e r ' s u t t e r a n c e may be i l l u s -
t r a t e d by an example taken from the d i a l o g i n f i g
2
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F i g 6: I n s t a n c e v a r i a b l e s and m e t h o d s i n t h e
m o t i o n c o n c e p t h i e r a r c h y The following d i s c u s s i o n of some of the p r o c e s s i n g
s i o n o f t h e e x a m p l e
a n a l y s i s - a process which on the one hand reduces
morphologi<al and s y n t a c t i c f e a t u r e s ( e g gender,
syntagmatic groups o f words and d i s c o n t i n u o u s verb
p r e d e f i n e d rules
The g e n e r a t e d s t r u c t u r e - the p r e t e r m i n a l s t r i n g
p a r s e r The s y n t a c t l c a n a l y s i s c o n s i s t s o f two
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I'.tg 7: An i n s t a n c e of TURN
w i t h c o p u l a v e r b s - uses a s u r f a c e grammar t o cope
w i t h w o r d order v a r i a t i o n s The o t h e r i s a c a s e -
d r i v e n a n a l y s i s s t r a t e g y w h i c h i s used f o r s e n -
t e n c e s c o n t a i n i n g v e r b s w i t h an a s s o c i a t e d c a s e
f r a m e
an access t o the case-frame l e x i c o n the case frame
the parsing i n the f o l l o w i n g manner: The al@orithm
t h o s e c o n s t i t u e n t s t h a t a r e p o s s i b l e c a n d i d a t e s
f i l l e d the p r o c e s s e n d s
d e e p case is d i v i d e d into a s y n t a c t i c and a seman-
that in order to fill the agent role a c o n s t i t u e n t
correspond t o t h a t o f the v e r b The semantic check
r e q u i r e s t h a t the noun o f the c o n s t i t u e n t f u l f i l l
s p e c i f i c deep c a s e T h i s i s a c c o m p l i s h e d t h r o u g h
t h e b u i l d i n g o f a SURF e x p r e s s i o n f o r t h e c o n s t i -
t u e n t , t h e t r a n s f o r m a t i o n o f t h i s e x p r e s s i o n i n t o
e x p r e s s i o n on t h e b a s i s o f t h e c o n c e p t u a l n e t
o b l i g a t o r y and t h e noun p h r a s e ' w h i c h t r u c k s ' f u l -
f i l l s b o t h t h e s y n t a c t i c and s e m a n t i c r e q u i r e m e n t s
t o f i l l t h i s s l o t S i n c e no o t h e r s y n t a c t i c c o n -
r e p r e s e n t a t i o n i s c o n s t r u c t e d The s t r u c t u r e i s normalized i n t o a DEEP s t r u c t u r e
q u a n t i f i e r s ( e g ' a ' , ' b o t h ' ) and q u e s t i o n opera
d e t e r m i n e d by a numeric v a l u e , w h i c h in some c a s e s
i s m o d i f i e d by t h e d e g r e e o f g e n e r a l i t y o f t h e
weaker than the more s p e c i f i c ( l u a n t i f i e r ' b o t h '
Trang 7I t Syntactic analysis
;; C a l l frame
I r l - i : l g e n t :
( d - l : r O l l - l i t t e r : O
r l l t r i c t i o n l
( i s a b e l : I I l i t - i s ISA I I VEHICLE)))
o b j e c t i v e :
source:
( e - i t role+marker: F
r e s t r i c t i o n s :
I l e l b d l : I | l i t - I t ISA e l THOROUGHFARE)))
l o o e t i v l :
( d - l : r o l e - n a r k e ~ : F
r l l t r i o t i u n l :
Llimbde: 11 l i E - e : ISA I t THOROUGHFARE)))
g o i I :
I d - L : r o l l - m a r k e r : F
r e s t r i c t i o n s :
Ileabds: I t l i t - i s ISA =| THOROUGHFAEE]))
time:
i n l t r u l e u t : )
;: AGENT p l r l l d
l l l l h d l : IS
L i t - i s AGENT
19
I t - s : [q+v: HUICU) I l e l b d l : x$ ( i t - a t XSA x0 TRUCEI)))|
;; SURF representation of i n p u t s e n t e n c e
I l l + d : EVENT
I t - s : ( g ' q t : E-ACT) ( l l i b d l : ItO l e E - i s ACT x l 0 G O B Y I l l
L d - l : r O l l + h i t :
( r i - e : agent:
L l a n b d l : IS
l i t - t : AGENT
=9
( t ' J : (qm+: HHICUI I l e n b d a : aS l e t - x : ISA sO TRUCE)))))
o b j e c t i v e :
e o u r c e :
l o c l t i v e :
goal:
t i l e :
p i t h :
i n l t r u a e n t : )
mud:
Id-a: tense:
t ; a l b d l : I t 1 l i t - e : TENSE I I 1 P E R F ) )
v o i c e :
( l a n b d l : I t 2 L e t - e : VOICE 112 ACTIVE)))|I
** i o r m e l i n n t * o n : T r e n l t o r l i n S i n t o DEEP representation
:: 9EEP s t r u c t u r e
I f - d : I t - q : ( f o r : (B-V: NRIEH) e l g ) l i t - R : ISA xt4 TRUCE))
I t - d : ( i - q : ( f o r : ( q - q t : G-ACTI 113) l e t - e : ACT I t S GO BY))
I f - e : r o l e - l i l t :
( r l - d : agent:
l i t - a : AGENT a13 e l 4 )
o b j e c t i v e
source:
l o c a t i v e :
p o l l :
t i M :
p a t h :
i a l t r u n e n t : )
nod:
I t - s : t e n s e : L e t - s : TENSE a t ] PERF) v o i c e : L e t - s : VOICE !13 ACTIVE))I
))
I i g v l l u a l i o n
:; E v a l u a t i o n of i formula u i t h the q u a n t i f i e r
(q-w MGICH)
;; E v l l u a t i o o t i t o r a u l l v i t h t h e q u a n t i f i e r
( q - q t R-ACT)
;; Object TfllICKI his not loved d u r i n g the e n t i r e scene
;: Evaluation of a formula w i t h the q u | n t i t i t r
I q - q t : R-ACT)
:; T i l t i n g nf • p a r t i a l l y i n l t a n t i e t l d t i l l frame
I f - e : P o l l - J i g s :
I r l - d " agent
[ a t - a : AGENT GG_BY TRUCKi|
o b j e c t i v e '
s o u r c e :
l o c a t i v e :
g o a l :
path:
instrument )
Iod:
t e n s e ( I f ' e : TENSE GO BY PEBF) v o i c e : e l f - i s VOICE GO_BY ACTIVE)J)
;; I n t e r v a l of consideration determined from tense land adverb)
:; Thi o b j e c t becomes v i s i b l e b e t l e l n t i l l p o i n t s SG l a d GS
;; The i n t e r v a l et consideration l O d i f i e d i n i c o u r d l n o l v i t h object t i l l i l : IGG 64)
;; Change determined b e t r o t h t i l l points SG and 57 3; Completed c e i l f r i l l
I f - I S r O l l - l i l t :
l + l - d : I g l f l t :
L i t - I S AGENT GO_BY t n g c x i )
o b j e e t i v e t SOurce:
l o c a t i v e : ( I f - i S LOCATZVE G0_BY nON DAOTONGGTGEET)
g o l l :
t i n t : path:
i n s t r u m e n t : ) nod:
annie: Let-s: TENSE GO_BY PERFI voice: ( i f - i s VOICE GO BY ACTIVE))) : ; + V e r i t i c a t i o n of event win p o l s i b i l
; ; O l s u l t Ot t h e E v a l u a t i o n
I f - d : I t - q : I f o r : (q-s: ITRUCNS)) el4) T) ) f - d : I t - q : ( f o r : Lq-qt: E-ACT) z t + l t i t - a s ACT xlS GO BY))
I t - I s r o l l - l i s t :
l r l - d : agent:
( i t - l : AGENT IT3 ZI4I
o b j e c t i v e : source:
l o c a t i v e :
l i t = a : LOCATIVE 113 *ON HbRTUNGSTREET) goal:
path:
instruments) lode
i f - I s t e n l l : ( i t - i s TERSE I t 3 PERF) voice: (at+at VOICE I t 3 ACTIVE}))))
la I n V l r l l n o r l i | i l l t i o n : T F l l l t O F l i n g i n t o SURF r l p r e s e n t l t i o n
; ; EUHF r l p r l l l n t l b i o + ot e l l i o t
l i t + d : EVENT
I t - I S ( q - q k : S-ACT) Llsabdl: xt3 L e t - t : ACT x l 3 GO_DYlll {d-e: r o l e - l i s t :
( r l - I : e v e n t :
I l e l b d l : I t S ( i t - l : AGENT 113 ( t - l ~ (B-a: ITGUCESII T ) I I
o b J e e t i v l : lOUrCl:
l o © I t i v a : ( l l l b d | : I t 3 l i t - a s LOCATIVE a l l tON HARTUNGSTREET))
g o a l :
p i t h :
i n e t r u l e n t : ) ned:
I d - a : t i n i e r ( l l a b d l : s t 3 [ i f + i s TENSE s t 3 PERFI]
v o i ~ e : ( l l u b d s : =13 L i t - i s VOICE a t 3 ACTIVE)))))
** E l l i p s i s g i n e r a t i o n
; ; E l l i p t i t t e d SURF r e p r e s e n t a t i o n of answer ( r l - e ~ I g e n t :
( 1 e l b a 1 : aS l i t - a s AGENT tO { t - l : ( q - s : (TRUCR2)] T ) ) )
o b j e c t i v e : lOUrce:
l o c a t i v e :
L l | a b d e : sO ( I t - I t LOCATIVE eO *ON UARTUNBSTREETI)
g o a l :
t i l l :
p i t h :
i n l t ? U l l n t i )
I I V l t b l ~ l l l t i O n
t t N P - G e n e r e t i o n f o r TOUCH2
;; The ggnerited DP f o r TRUCRS i s :
(t-q: ( t o r : l q - q t : A) 1IS) I f - o : AND Let-is ISA l I B TRUED) ( i f - e ~ BEF ItS LIGGT-COLORBDI)I
;; V e r b l I i l l d i t r u c t u r e Of easier (SENTENCE IAGEDT (HP (HP (H: SOl A LIGHT-COLORED (ELLIPSIS THUCE))I) (LOCATIVE IPP *OH IflP (Ms SOL HARTUNGSTEEETIIII
*l S u r f a c e t r l n s f o r m i t i o n i
A LIGNY+COLOREG ONE ON GARTBNGBTNEET
F i g 8: Annotated example Lnteraction
Trang 8S i n c e , i n t h e example d i s c u s s e d , t h e q u e s t i o n
o p e r a t o r ' w h i c h ' i s s t r o n g e r t h a n t h e e x i s t e n t i a l
q u a n t i f i e r f o r v e r b s ' E - A C T ' , t h e s t r u c t u r e i s
r e a r r a n g e d
The t a s k o f e v a l u a t i n g a OEEP f o r m u l a i s g o v e r n e d
by a g e n e r a t e and t e s t s t r a t e g y G e n e r a t e and t e s t
p r o c e d u r e s can De v i e w e d as b e i n g a c t i v a t e d by
p a t t e r n - d i r e c t e d i n v o c a t i o n and d i f f e r f r o m each
o t h e r i n t h a t t h e g e n e r a t e p r o c e d u r e s a s s i g n
i n t e r n a l o b j e c t i d e n t i f i e r s t o v a r i a b l e s i n DEEP
f o r m u l a s , w h i l e t h e t e s t p r o c e d u r e s y i e l d two
v a l u e s , t h e f i r s t o f w h i c h i s e i t h e r a f u l l y
i n s t a n t i a t e d f o r m u l a e q u i v a l e n t t o t h e i n p u t f o r -
w h i c h i n d i c a t e s t h e t r u t h v a l u e o f t h e i n p u t f o r -
mula i n t h e r a n g e [ 0 , 1 ] In t h e i n t e r p r e t a t i o n
t h a t a t e s t a t t e m p t a c t i v a t e s g e n e r a t e p r o c e d u r e s
w h i c h i n t u r n c a l l t e s t p r o c e d u r e s and so on
A c l o s e r l o o k a t o u r example shows t h a t a f t e r t h e
f i r s t t e s t a t t e m p t has d i s c o v e r e d a s t r u c t u r e c o n -
r e p r e s e n t i n g t h e noun p h r a s e ' w h i c h t r u c k s ' - a
package o f g e n e r a t e p r o c e d u r e s i s a c t i v a t e d t o
p r o d u c e t h e s e t o f o b j e c t i d e n t i f i e r s d e n o t i n g t h e
r e f e r e n t i a l set of o b j e c t s t h a t are t r u c k s - h e r e
t h e n r e c u r s i v e l y s e n t t o a t e s t p r o c e s s w i t h t h e
v a r i a b l e ' w 1 4 ' r e p l a c e d by e l e m e n t s o f t h e r e f e r -
ence s e t f o r t r u c k s one a f t e r t h e o t h e r
The n e x t f o r m u l a t o be t e s t e d r e q u i r e s t h e g e n e r a -
S i n c e e v e n t s a r e n o t r e p r e s e n t e d i n f u l l y
i n s t a n t i a t e d f o r m b u t r a t h e r must be e x t r a c t e d
f r o m t h e g e o m e t r i c a l scene d e s c r i p t i o n , a s p e c i a l
s e t o f p r o c e d u r e s - t h e methods s p e c i f i e d i n t h e
v e r b f l a v o r h i e r a r c h y - i s a c t i v a t e d (See s e c t i o n
3 4 2 f o r how t h i s p r o c e s s f u n c t i o n s , )
A v e r i f i c a t i o n o f an e v e n t GO BY i s p o s s i b l e o n l y
f o r TRUCK2 The a d d i t i o n a l ~ n f o r m a t i o n e x t r a c t e d
d u r i n 9 t h e p r o c e s s o f v i s u a l s e a r c h - t h e s p e c i f i c
l o c a t i o n o f t h e e v e n t - i s r e c o r d e d i n t h e l o c a -
t i v e s l o t
D u r i n g t h e f o r m a t i o n o f t h e r e s u l t o f t h e e v a l u a -
t i o n , t h e s y s t e m , g u i d e d by g e n e r a l h e u r i s t i c s ,
d e c i d e s w h e t h e r t h e a d d i t i o n a l d e t a i l w i l l cause
t o o ~ r e a t a c o m p l e x i t y i n t h e answer o r n o t [ 1 1 ]
I n t h i s case t h e c o m p l e x i t y i s s u i t a b l e and t h e
l o c a t i o n w i l l be m e n t i o n e d i n t h e a n s w e r
The word ' w h i c h ' i s d e f i n e d as q u a n t i f i e r t h a t
causes a d e s c r i p t i o n o f a s e t o f o b j e c t s t o be
r e t u r n e d ( i n s t e a d o f a t r u t h v a l u e ) Thus t h e s e t
o f r e f e r e n c e o b j e c t s f o r w h i c h t h e p r o p o s i t i o n i n
q u e s t i o n c o u l d be v e r i f i e d , i e TRUCK2, i s sub-
s t i t u t e d f o r t h e noun p h r a s e ' w h i c h t r u c k s '
The r e s u l t i n g DEEP e x p r e s s i o n i s t r a n s f o r m e d by
t h e i n v e r s e n o r m a l i z a t i o n p r o c e s s i n t o a SURF
e x p r e s s i o n In o r d e r t o v e r b a l i z e e x t e n d e d
r e s p o n s e s i n a manner b o t h i n f o r m a t i v e and c o n c i s e
as p o s s i b l e , t h e e l l i p s i s g e n e r a t i o n p r o c e s s
e l i d e s t h o s e p a r t s o f t h e s e m a n t i c r e p r e s e n t a t i o n
o f c o m p l e t e r e s p o n s e s t h a t a r e i d e n t i c a l t o t h e
s t o r e d r e p r e s e n t a t i o n o f t h e q u e s t i o n [ ? ]
The v e r b a l i z a t i o n component p r o d u c e s a s t r i n g o f
c a n o n i c a l words and t h e i r g r a m m a t i c a l f e a t u r e s
u s i n g t r a n s l a t i o n r u l e s a t t a c h e d to the v a r i o u s
c a t e g o r i e s of S U R F e x p r e s s i o n s , A s p e c i a l s u b c o m -
p o n e n t p r o v i d e s for t h e g e n e r a t i o n of noun p h r a s e s
as d e s c r i p t i o n s o f domain i n d i v i d u a l s , i n o u r
s i n c e n e i t h e r t h e s y s t e m nor t h e u s e r has a l r e a d y
i m p l i e d by t h e e x i s t e n t i a l a s s u m p t i o n s s u p p l i e d by
t h e a p r i o r i u s e r model ( c f [ ? ] ) I n s t e a d , t h e
i n d e f i n i t e NP a l i g h t - c o l o r e d t r u c k ' i s gen-
e r a t e d , u s i n g t h e p r o p e r t y ' l i g h t - c o l o r e d ' as an
i n i t i a l c h a r a c t e r i z a t i o n
F i n a l l y t h e " s u r f a c e t r a n s f o r m a t i o n ' component [ 1 ]
s t a n d a r d word o r d e r o f t h e u t t e r a n c e and t h e
c o r r e c t l y i n f l e c t e d f o r m s o f t h e c a n o n i c a l w o r d s
We have a t t e m p t e d to show t h a t case r o l e f i l l i n g
r e s p o n s e can be r e g a r d e d as a s i d e e f f e c t o f t h e
v i s u a l s e a r c h n e c e s s a r y t o answer q u e s t i o n s r e f e r -
r i n g t o a v i s u a l l y p r e s e n t domain o f d i s c o u r s e A new method f o r t h e r e p r e s e n t a t i o n o f t h e r e f e r e n -
t i a l s e m a n t i c s a s s o c i a t e d w i t h l o c o m o t i o n v e r b s has been p r e s e n t e d i n t h e f r a m e w o r k o f o b j e c t -
The a p p r o a c h p r e s e n t e d has been u s e f u l i n e x t e n d -
i n g t h e c o m m u n i c a t i v e c a p a b i l i t i e s o f t h e d i a l o g
s y s t e m HAM-AN$ as an i n t e r f a c e t o a v i s i o n s y s t e m
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