Conclusion - Computational Linguistics and Talking Robots - page 233

12. Conclusion
For natural language communication to be comfortable, the use of the signs
must be flexible (robust). Therefore, one challenge in building a talking robot
is to reproduce the flexibility which is integral to human communication.
In DBS, this flexibility has three aspects. The first is the ability (i) to change
levels of abstraction effortlessly and (ii) to use language indirectly as in analo-
gies, metaphors, and so on. This aspect is based on inferences. Derived and ap-
plied automatically, the inferences are triggered by the evaluated data stream
provided by the agent's cognition.
The second aspect inheres in the nature of pattern matching. This aspect
of flexibility is handled by schemata which utilize restricted variables, core
values, and the semantic relations of structure, enabling highly differentiated
retrieval. Pattern matching is used, for example, in recognition, when raw data
are classified by concept types, and in retrieval, when schemata activate rele-
vant contents in the database.
The third aspect is the ability of the hearer to ask for clarification. This is
another aspect handled by inferences.
These aspects of flexibility result combined in practically unlimited expres-
sive power, for example, in data mining. In an alert DBS robot, recognition,
subactivation, intersection, and inferencing are continuously running and pro-
vide autonomous control with the stored world knowledge and the experiences
relevant for maintaining the agent in a state of balance.
12.1 Level of Abstraction
The construction of an artificial agent with language may be compared to the
construction of an airplane. For both, there is a natural prototype with which
they share certain crucial properties and from which they differ in others.
An airplane (artificial model) and a bird (natural prototype) have in common
that both stay airborne according to the same principles of the theory of aero-
dynamics. They differ, however, in that lift and propulsion are combined in the