Roland Hausser’s book addresses the mechanisms of Natural Language communication with speaking robots of the future. Although it focuses on language, it also tries to take into account a few multi-modal aspects of communication .
The book has a very strict organisation : four parts (language theory, grammar theory, morphology and syntax, semantics and pragmatics), each made up of six chapters, each of which, in turn, contains five sections.
An Introduction first presents the “SLIM” linguistic theory (meaning Surface compositional Linear Internal Matching), stating its four basic principles: surface compositionality (methodological principle), derivational order’s strict linearity relative to time (empirical principle), utterance interpretation and production analysed as cognitive processes (ontological principle), reference modelled in terms of matching an utterance’s meaning with context (functional principle).
The first part (language theory) develops a view of language illustrated by the description of a robot (Curious by name). This theory (SLIM) relies upon cognitive semantic primitives, a sign theory, along with their functional integration within generative and interpretative processes.
More precisely, Chapter 1 immediately positions the topic within the Human-Computer Interaction (HCI) paradigm, viewing computational linguistics as basically pluri-disciplinary. The author distinguishes two branches of AI (the classic, formal one, and the robotics-based one, the difference being that, for the latter, the environment undergoes perpetual, unpredictable changes). Two kinds of Artificial Intelligence yield two kinds of HCI, to which he adds a third case of communication, within the Virtual Reality framework. Following the classic distinction between various levels (phonology, morphology, lexicon, syntax, semantics and pragmatics), the author, who somehow mixes computer processing and Internet aspects, presents the innovative features of present-day publications (from CD-ROM to SGML).
Taking as examples the search in indexing mechanisms in data bases, along with automatic translation (presently limited to on-line help, crude translation or restricted language), Chapter 2 presents the essentials of Natural Language Processing, and underlines phenomena which call for linguistic solutions at the various aforementioned levels, reminding the reader about the alternative between “smart” and “solid” solutions (which reminds us of Tomita’s distinction between “interesting” and “useful” problems[1]).
Chapter 3, starting from the connections between understanding and communication on the one hand, and between understanding and perception on the other, leads to a proposal for an “iconic” representation of objects, which, although it is somewhat crude, seems to be efficient in the current field. However, I found that the role of lexical categories is treated in an over-simplified manner, and the limits of this kind of representation could have been more seriously explored (raises such questions as: can all sorts of objects be described in this way? How does one deal with more or less abstract entities?).
The reference phenomenon is then considered, using a mechanism of best match between representations of known objects in the world and representation from linguistic descriptions. This means that one elaborates on relations between literal meaning, compositionality and pragmatics aspects. Here, other language theories are presented, (mainly Chomsky’s and Grice’s), but the author’s own theory is also compared with the traditional semantic theories: those of Frege, Pierce’ Saussure, Bühler, and of Shannon and Weaver, detailing their formal and methodological foundations, and showing their connections with the proposed one. This presentation remains very “reference-oriented”, and the study of conditions for success in HCI could have gone deeper...
[1]. The former have no obvious solution, call for the development of sophisticated theories, or make it possible to exhibit general linguistic principles, and can be treated by a small number of general rules (e. g. relativisation, causation, group movement). In contrast, "useful" problems are those for which obvious solutions exist, or those for which no general principle can be exhibited; one just has to add specific rules to solve each one of those problems (punctuation, expression of dates, idioms). The latter kind of problem is difficult to anticipate, and requires very large amounts of knowledge.
Note that it is just as essential to solve both kinds of problems if one wants running applications! However, if one is mainly interested in theoretical aspects, it will be possible to neglect problems of the second kind, for which simple solutions potentially exist, but would be costly to implement. Moreover, the attitude of some linguists, who are constructing a complete catalogue of all figures of discourse (Gross, Mel'cuk) implies that all problems are of the second kind.
