Parsing

Parsing Meaning

Parsing, sometimes referred to as syntax analysis, is the process of dividing language (such as a sentence) into its grammatical components. In the field of linguistics and syntax, the grammatical components of a sentence are named constituents.

The term parsing is a verb (infinitive = to parse), which comes from the Latin word pars (meaning part of, as in part of speech).

The action of parsing itself can be done with the help of visual diagrams, known as parse or syntax trees, or with computer software. Creating parse trees helps us see the syntactical relationships between constituents.

Fig 1. Constituents are the building blocks of language

Parsing Definition

In summary, parsing can be defined as:

Parsing in Linguistics

Parsing is a multidisciplinary technique used in linguistics, AI (artificial intelligence), data analysis, Natural Language Processing, and software development. Although parsing is commonly associated with Informational Technology (IT) today, it is rooted in and originates from linguistics.

Parsing in linguistics involves highlighting all the constituents in a sentence and taking note of things like tense and verb conjugations. Analyzing language in this way helps us understand the intended meaning and purpose of a sentence and the relationship between words.

For example, the most common constituent relationship within a sentence is the subject + its predicate. The subject is who/what the sentence is about, and its predicate is the part of a sentence that adds detail or information to the subject (predicates usually contain a verb).

Parsing helps us to recognize which group of words is the subject and which ones are the predicate.

You've probably gathered by now that constituents play a vital role in the parsing. So, let's take a closer look at them now.

Constituents

Constituents are the units of language that work together to build a sentence. They can be morphemes, phrases, and clauses. The smaller constituents (e.g., morphemes) combine to form larger constituents (e.g., phrases), which can again combine to form larger constituents (e.g., clauses or predicates).

For example, in the above example (The woman with the sparkly black backpack is my sister), we highlighted two main constituents, but those larger constituents can be further divided into their own constituents.

Parsing Techniques

In linguistics, the most common way to conduct parsing is by creating a parse tree (aka a syntax tree). Parse trees comprise branches and root nodes, branch nodes, and leaf nodes.

Typically, the main sentence is the root node as it doesn't have any branches above it, the phrases are the branch nodes, and individual words are the leaf nodes. The branches are the lines that show the relationship between the nodes.

• Root nodes - Root nodes should appear at the top of the tree and have no nodes or branches above them. There can only be one root node in a sentence. A root node is the parent to branch nodes.

• Branch nodes - These are typically phrases or individual words that appear below the root nodes. Branch nodes act as parents to leaf nodes.

• Leaf nodes - Leaf nodes are the last element in a parse tree and cannot be the parent to any other nodes. They are individual words.

Parsing Examples

Now that you know all about parse trees let's look closely at an example. You should be aware that parse trees usually follow the same key:

S = Sentence

NP = Noun Phrase

VP = Verb Phrase

AdjP = Adjective Phrase

AdvP = Adverb Phrase

PP = Prepositional Phrase

D = Determiner

N = Noun

V = Verb

Adj = Adjective

Adv = Adverb

P = Preposition

Fig 2. An example parse tree

• Root node - The woman with the sparkly black backpack is my sister (sentence)

• Branch nodes -

  • The woman with the sparkly black backpack (noun phrase)

  • with the sparkly black backpack (prepositional phrase)

  • the sparkly black (adjective phrase)

  • is my sister (verb phrase)

  • my sister (noun phrase)

• Leaf nodes -

  • the (determiner)

  • woman (noun)

  • with (preposition)

  • the (determiner)

  • sparkly (adjective)

  • black (adjective)

  • backpack (noun)

  • is (verb)

  • my (determiner)

  • sister (noun)

Parsing Sentences

Here are some further examples of conducting constituent parsing analyses of sentences using parse trees.

Example 1.

Fig 3. A parse tree

Example 2.

Fig 3. A simple parse tree

Parsing Emails

Language parsing plays a significant role in many aspects of our daily lives, perhaps without us even realizing it. One aspect is in the filtering of emails.

Email parsing is the process of using computer software to identify particular words or phrases within an email. This process can automatically filter emails into folders, such as 'spam' or 'social,' and help us find and sort emails quickly.