6 - The implementation

Summary

This chapter will describe the first implementation of the Systemic Linguistic Approach to Natural-language Generation (SLANG-I). SLANG-I has been implemented as a production system using the production language OPS5. Since many OPS5 rules appear in this chapter, a short introduction to OPS5 has been provided in Appendix A.

This chapter is divided into five sections. The first is an overview of the system as a whole. It will provide high-level descriptions and explanations for the mechanisms used in the implementation. The second section is a detailed description of the System Network – OPS5 Rule Translator (SNORT) which outputs the grammar in the form of OPS5 production rules that can be used by SLANG-I. The text-generation system itself–SLANG-I–is described in detail in the third section. The fourth and fifth sections look at the limitations of this implementation and some possible alternatives respectively. Finally, a summary is given.

Overview

The purpose of this section is to provide a high-level overview of SNORT and SLANG-I before getting down to details in the next two sections. To a large extent this is made necessary by the interdependence between these two components. It is impossible to motivate the output of SNORT before explaining to a certain extent how SLANG-I works, and similarly SLANG-I cannot be explained before it is understood how the grammar is represented in OPS₅ production rules. This section consists of four parts: first, a presentation of the abstract architecture of SLANG-I; second, a discussion of the OPS5 productions representing the systemic grammar; third, a description of the data structures used by SLANG-I; and fourth, a brief look at the control strategy used to coordinate the text-generation process.