Natural Language Processing · TEE · papers
Q6c · NLU and NLG working together
2024-12-03 · final · recovered AI paper
Previous examination · complete worked answers
Question. Explain how NLU and NLG work together for meaningful human–machine communication. [5 marks]
Answer
Natural language understanding (NLU) maps language into an interpretation useful for a task: intents, entities, semantic relations or another meaning representation. Natural language generation (NLG) produces human-language output from data, a representation or another source.
“Book a ticket to Pune tomorrow.”
NLU: intent=book; destination=Pune; date=tomorrow
Application: search available journeys
NLG: “Here are the available journeys to Pune.”
| Feature | NLU | NLG |
|---|---|---|
| Direction | Language → interpretation | Data/representation → language |
| Main concern | Meaning, intent, ambiguity | Content choice, organization, fluent wording |
| Example | Find destination in a request | Write the booking confirmation |
| Common failure | Wrong destination or sense | Unclear, unsupported or ungrammatical output |
NLG stages in a classical pipeline
- Content determination: choose facts to communicate.
- Data interpretation: identify relationships or trends.
- Document planning: organize facts in a useful order.
- Sentence aggregation: combine related facts without repetition.
- Lexical and grammatical realization: choose words and construct grammatical sentences.
- Presentation: format the generated message for its audience.
For a weather report, facts {city=Pune, temperature=28°C, rain=yes} can become “Pune will have rain with a temperature of 28°C.” NLU would instead extract facts or intent from an incoming language message.
NLU = language se meaning andar. NLG = data se language bahar.