Natural language
processing is a series of tools that are built on
the principles of linguistics, that try to get computers to
understand the construct of language. The major levels of linguistic
structure are phonetics, phonology, morphology, syntax, semantics,
and finally pragmatics. Starting at the most basic
are phonetics and phonology. Both of these levels have
to do with the physics of making sounds and the combination
of sounds in speech. These levels are outside the scope of NLP applications in this course. The next level, morphology, deals with the structure of individual words and
how the basic units identified in phonetics and phonology are combined
to produce words. Syntax then describes
the structure of how we combine multiple words into
phrases and sentences. Think of this like grammar. Sentences should have a subject, an object, and a verb. This is distinct from semantics, which describes the actual meaning
of words and phrases. Finally, pragmatics covers
the higher level aspects of communication to capture
the meaning of texts in the context of
real-world communication. Not included in this hierarchy
is the concept of the lexicon, the actual list of words and
phrases used in a language. As you can tell, linguistics is
a very complicated field. We'll cover each of these levels
of linguistics in more depth in other videos to show you how they relate to the practice of
natural language processing.