Siksha Sarovar

Siksha Sarovar (sikshasarovar.com) is a free educational web application that helps students in India learn programming and prepare for academic and competitive exams. The platform offers structured coding courses (C, C++, Python, Java, HTML, CSS, PHP, Power BI, AI, Machine Learning, Data Science), complete university curriculum notes for BCA/MCA students with previous year question papers, Class 10 and Class 12 CBSE/HBSE school notes, and dedicated preparation material for SSC, UPSC, Banking, Railway and other government exams. Browsing the site is completely free and requires no account. Users may optionally sign in with Google solely to save their learning progress, quiz scores and personal preferences across devices.

Privacy Policy | Terms of Service | Contact Siksha Sarovar | About Siksha Sarovar

v4.0.9 · PWA
Siksha Sarovar logo
Siksha Sarovar
Your Learning Universe

Siksha Sarovar is a free e-learning platform for coding courses, BCA university notes and competitive exam preparation. Optional Google sign-in saves your learning progress across devices.

Initializing knowledge base…
Compiling modules 0%

Unit 3 — Semantic Processing

Lesson 22 of 34 in the free Artificial Intelligence notes on Siksha Sarovar, written by Rohit Jangra.

Semantic Processing

Once a sentence is syntactically parsed, semantic processing determines its literal meaning — mapping words and structure onto a formal meaning representation, independent of context outside the sentence.

From Syntax to Semantics

Example: "The cat chased the mouse" becomes Chase(Cat1, Mouse1) AND Isa(Cat1, Cat) AND Isa(Mouse1, Mouse)

Core Tasks in Semantic Processing

TaskDescription
Word-sense disambiguationChoosing the correct meaning of a word with multiple senses ("bank" = riverbank vs financial bank)
Semantic role labellingIdentifying who did what to whom (agent, patient, instrument)
Compositional semanticsBuilding the meaning of a sentence from the meanings of its parts and how they combine
Reference resolution (local)Resolving what a noun phrase refers to within the sentence itself

Word-Sense Disambiguation Example

SentenceCorrect sense of "bank"
"I deposited money in the bank"Financial institution
"We sat by the river bank"Land alongside a river

The correct sense typically depends on surrounding words ("deposited money" vs. "river") — semantic processing must use this local context to disambiguate.

Semantic Roles (Case Grammar)

RoleMeaningIn "The cat chased the mouse"
AgentThe doer of the actionCat
Patient/ThemeThe entity acted uponMouse
InstrumentThe means by which the action is done(none here)
LocationWhere the action occurs(none here)

Handling Semantic Anomaly

A sentence can be syntactically perfect but semantically anomalous: "Colourless green ideas sleep furiously" (Chomsky's famous example) parses fine grammatically but violates semantic constraints (ideas don't have colour, colourless things can't also be green, ideas don't sleep). Detecting such violations is part of the semantic-processing task.

Output: A Formal Meaning Representation

Semantic processing typically produces a structure such as predicate logic, a semantic network, or a frame-based representation (all covered in Unit 2) — connecting NLP directly back to the knowledge-representation techniques studied earlier in the course.