Conclusions

In the twentieth century, syntax was in the center of the linguistic research, and the approach to syntactic issues determined the structure of any linguistic theory. There are two major approaches to syntax: the constituency, or phrase-structure, approach, and the dependency approach. The constituency tradition was originated by N. Chomsky with the introduction of the context-free grammars, and the most recent development in this tradition is Head-driven Phrase Structure Grammar theory. The dependency approach is used in the Meaning  Text Theory by Igor Mel’čuk. Both approaches are applicable for describing linguistic phenomena in many languages.

III. Products of computational linguistics: present and prospective

FOR WHAT PURPOSES do we need to develop computational linguistics? What practical results does it provide for society? Before we start discus-sing the methods and techniques of computational linguistics, it is worthwhile giving a review of some existing practical results, i.e., applications, or products, of this discipline. We consider such applications in a very broad sense, including in this category all known tasks of word processing, as well as those of text processing, text generation, dialogue in a natural language, and language understanding.

Some of these applications already provide the user with satisfactory solutions for their tasks, especially for English, while other tasks and languages have been under continuous research in recent decades.

Of course, some extrapolations of the current trends could give completely new types of systems and new solutions to the current problems, but this is out of scope of this book.

Classification of applied linguistic systems

Applied linguistic systems are now widely used in business and scientific domains for many purposes. Some of the most important ones among them are the following:

       Text preparation, or text editing, in a broad sense, particularly including the tasks listed below:

–          Automatic hyphenation of words in natural language texts,

–          Spell checking, i.e., detection and correction of typographic and spelling errors,

–          Grammar checking, i. e., detection and correction of grammatical errors,

–          Style checking, i. e. detection and correction of stylistic errors,

–          Referencing specific words, word combinations, and semantic links between them;

       Information retrieval in scientific, technical, and business document databases;

       Automatic translation from one natural language to another;

       Natural language interfaces to databases and other systems;

       Extraction of factual data from business or scientific texts;

       Text generation from pictures and formal specifications;

       Natural language understanding;

       Optical character recognition, speech recognition, etc.

For the purposes of this book, we will give here only a short sketch of each application. Later, some of these topics, with more deep explanations, can be touched upon once more.