Reference in Dialogue
Jens Stephan
What is Reference
• Some sort of Relation
between
Pele
He
That guy
The best Soccer
Player ever
Problems of using Reference
• What am I referring to, how and why?
(rules of engagement, intentions,…)
• How do I map it into my word? (reference
resolution)
• How do I know all participants did it the
same? (grounding, clarification,…)
• And there is no way around it…
Anaphora & Co-Reference
• Anaphora are a special case of referring
expressions
• There work done on this topic using
various strategies like
– Syntax
– Semantics / world and special knowlegde
– Intentions of the participants
– Center of Attention (Grosz)
Problem: not enough
• Most work is done on personal pronoun
resolution
• There are lost of other anaphoric referring
expressions (Eckert & Strube), especially
in spoken dialogue
• Lots of coreferrence expressions don’t
even have pronouns
Intention + Attentional State
• The attentional state introduced by Grosz
is a great idea, because:
-It is intuitively a very plausible approach
-People that know a lot would never be able to talk with you without it
-It could even explain parts of Grice’s Conversational Implicatures
But:
-I think it is rather a property of the participants internal state than a
property of the discourse itself
-It does not have an Interface to Speech Act theory yet (at least
in the original)
Problems in General
• Reference and Co-Reference are not
researched broad enough on actual
Dialogue Data
• A few phenomena received a lot of
attention, … and even those are not
solved
• The type of references used is very
domain specific
Example: Dialogue Agent
Algorithm: PRO -> last <obj> (last NP algorithm)
Initial KB:
Fries <obj>
Potatoes <obj>
Ketchup <obj>
want <user, obj>
Cheeseburger <obj>
Dry Bread
Potatoes <obj>
with <obj, obj>
S> What would you like?
U> I want the juicy one: the
cheeseburger
S> Would you like some fries?
U> No, I want some potatoes with it
S> Medium fries and medium potatoes?
U> No, I want them small and no fries I
said
S> Ok, medium potatoes. Anyhing else
with it?
U> You know what, forget it
Example: Dialogue Agent
Algorithm: PRO -> last <obj> (last NP algorithm)
Initial KB:
Fries <obj>
Potatoes <obj>
Ketchup <obj>
want <user, obj>
Cheeseburger <obj>
Dry Bread
Potatoes <obj>
with <obj, obj>
S> What would you like?
U> [I want the juicy one]: the
cheeseburger
S> Would you like some fries?
U> No, I want some potatoes with it
S> Medium fries and medium potatoes?
U> No, I want them small and no fries I
said
S> Ok, medium potatoes. Anyhing else
with it?
U> You know what, forget [it]
What would we need to do to make
it working?
• Suggestions, Questions? Discussion
please 