Introduction: How to Build a Talking Robot - Computational Linguistics and Talking Robots - page 12

conditions relative to a set-theoretic model. As a consequence, the mean-
ings in DBS have concrete realizations in terms of software and hard-
ware procedures, while those of Truth-Conditional Semantics do not (cf.
FoCL'99, Chaps. 3-6; NLC'06, Chap. 2).
4. Database:
In DBS, the content derived in the hear mode or by inferencing is stored
in a content-addressable memory, called Word Bank. Most current appli-
cations, in contrast, use a coordinate-addressable database, for example,
an RDBMS, if they use a database at all. The crucial property of content-
addressable memories is that they are good for content which is written
once and never changed. Given that a cognitive agent is constantly chang-
ing, this seems to be a paradoxical quality. It turns out, however, that it is
the no-rewrite property which allows for a simple, powerful definition of
inferences in DBS (Chaps. 5, 6, 10, 11). 30
5. Data Structure:
DBS uses flat (non-recursive) feature structures with ordered attributes.
Current systems of Nativism, in contrast, use recursive feature struc-
tures with unordered attributes to model “constituent structure” trees (cf.
FoCL'99, Sect. 8.5). Flat feature structures with ordered attributes are of
superior computational efficiency for a wide range of operations, such as
pattern matching, which is ubiquitous in Database Semantics (Sects. 3.4,
4.2, 4.3, 5.2, 6.5).
6. Intention
DBS reconstructs the phenomenon of intention as part of an autonomous
control designed to maintain the agent in a state of balance. This is in con-
trast to other schools of linguistics and philosophy who refer eclectically
to Grice (1957, 1965, 1989) whenever the need arises, but are oblivious
to the fact that Grice's elementary, atomic, presupposed notion is of little
use for the computational reconstruction of intention and, by Grice's own
definition (5.1.1), of meaning in a cognitive agent.
7. Perspective
The speak and the hear modes in the agent-oriented approach of DBS pro-
vide the foundation for modeling the perspectives of the speaker/writer and
the hearer/reader in dialogue/text. They are (i) the perspective of an agent
recording a current situation as a content, (ii) a speaker's perspective on
a stored content, and (iii) the hearer's perspective on a content transmit-
30 The additional means of coreference-by-address, coded both declaratively and as pointers, relates
new content to old, satisfying the desiderata (i) of a declarative specification (using symbols) and (ii)
of an efficient implementation (using pointers). Cf. Sect. 4.4.