Phases of NLP

- Overview 

NLP works by analyzing text through several layers of analysis, from breaking it down into words and their base forms (lexical and morphological analysis) to understanding sentence structure (syntax analysis) and meaning (semantic analysis), and finally to interpreting intent within a larger context (discourse and pragmatic analysis). 

This hierarchical process allows computers to process and understand human language by first handling the basic components and building up to deeper comprehension. 

Phase 1. Lexical and morphological analysis:

• Tokenization: The process of breaking a text into smaller units, or "tokens," such as words, punctuation, and numbers. For example, "Hello world!" becomes ["Hello", "world", "!"].
• Morphological analysis: This involves understanding the structure of words. It includes tasks like stemming (reducing words to a rough root, e.g., "running" to "run") and lemmatization (reducing words to their base or dictionary form, e.g., "ran" and "running" both become "run").
• Part-of-Speech (POS) tagging: Assigning a grammatical category (like noun, verb, or adjective) to each token.

Phase 2. Syntax analysis (parsing): 

• Grammatical structure: This stage analyzes the grammatical rules of a sentence to understand how words are related to each other.
• Parsing: It involves building a structure (often a parse tree) that shows the relationships between words in a sentence, such as which words are the subject, verb, and object.

Phase 3. Semantic analysis:

• Word sense disambiguation: Determining the correct meaning of a word that has multiple meanings based on its surrounding context. For example, understanding the difference between "I'm going to the bank" (financial institution) and "The river bank is eroding".
• Meaning extraction: Understanding the literal meaning of phrases and sentences, independent of the broader context.

Phase 4. Discourse and pragmatic analysis: 

• Discourse analysis: This layer goes beyond individual sentences to look at how sentences relate to each other in a larger text.
• Pragmatic analysis: This is the final and most complex step, focusing on the intended meaning and purpose of the text beyond its literal words. It involves understanding real-world context, cultural nuances, and the speaker's intent. For example, "Can you pass the salt?" is not a literal question about ability, but a request to pass the salt. 

[More to come ...]