Natural Language Processing

It's been a long time since I wrote a post. So here comes anjusthoughts with a Bang... This post is inspired by one of my colleagues
As we all know, Language is a means of communication. Languages can be broadly classified into two namely:

• Natural languages are the languages that people speak, such as English, Spanish, and French. These languages are not designed and are evolved naturally.
• Formal languages are languages that are designed by people for specific applications.

Natural Language Processing

Natural Language Processing or NLP consist of a set of tasks computers perform to understand natural language and generate natural language. The computer is used for the interpretation and analysis of Natural Language.

Natural Language Generation (NLG)

NLG is when a computer writes text of the same quality as that of a human being. It can also be termed as Text Generation.

Natural Language Understanding (NLU)

NLU attempts to understand the meaning behind a written text. NLU faces the challenge of understanding a text without ambiguity, while understanding the rules of the language used. So tow issues must be addressed:

• What to say- What we are going to talk about
• How to say- It deals with formulating grammatically correct sentences.

Stages of Natural Language Processing

Natural Language Processing can be divided into three stages namely:

1. Syntactic Analysis
2. Semantic Analysis
3. Contextual Representation

Now let’s look into each of these stages in detail:

1. Syntactic Analysis

In this phase the input is being checked to ensure that its syntax is correct. This is done based on a grammar. The following are the two simple methods used:

1. Context Free Grammars(CFG)

Consider the following sentence:

“The cat eats rice.”

The parse tree for the above sentence is as follows:

The list of rules for the construction of the tree are:

S -> NP VP
NP -> DET N | DET ADJ N
VP -> V NP

The above sentence consists of:

DET -> the

ADJ-> big|fat

Top- Down Parser

The parser starts with the symbol S and attempts to rewrite the sentence into a sequence of Terminals. The structure of CFG consists of:

• LHS- It consist of Non terminals or symbols. They cannot be expanded further.
• RHS- These include terminals or non terminals.

1. Semantic Analysis

It involves the formulation of a logical representation of the sentence. The meaning of the sentence must be extracted for such a representation.

2. Contextual Representation

As its name implies the sentence is analysed based on the context. The logical representation is converted into a Knowledge representation. 

More updates about Natural Language Processing in the Next Post....

I am Thankful to all those who said NO. Because of them I did it myself.