Natural Language Processing Flashcards
What is Natural Language Processing (NLP)?
A subfield of [linguistics, computer science, information engineering and AI] concerned with the interactions between computers and human languages.
What are some goals of Natural Language Processing?
- Improve human-computer communication
- Allow people to program computers in natural language
- Distill knowledge from texts
Who developed the ELIZA program?
Joseph Weizenbaum in 1966
What was ELIZA originally meant to be a parody of?
A Rogerian psychoanalyst
How does ELIZA generate responses?
- Scans input sentences for keywords
- Analyzes input according to transformation rules
- Generates responses based on reassembly rules
True or False: ELIZA has a deep understanding of the conversation.
False
What kind of responses does ELIZA use?
Stock answers based on previously mentioned keywords
What is an example of a transformation rule in ELIZA?
Predefined responses are triggered by a sentence containing keywords (e.g., ‘I feel’)
What was the impact of ELIZA?
- One of the best-known AI chatbots
- Claimed by some to have passed the Turing Test
What is PARRY?
A program developed in 1972 to imitate a paranoid schizophrenic
How did PARRY improve upon ELIZA?
It addressed the lack of internal world tracking in ELIZA
What is the main function of SHRDLU?
A natural language interface to a block world allowing users to perform tasks and answer questions
What language was first able to solve simple high school math problems posed in natural language?
STUDENT assumed that every sentence is an equation, used trigger words to identify the parts of the equation:
* „is“ → equates two entities
* „per“ → divides two entities
(Bobrow 1964)
Why is Natural Language Processing considered hard?
- Ambiguity at lexical, syntactic and semantic levels (e.g., hidden meanings, jokes, puns)
What are traditional NLP tasks?
- Word Segmentation
- Part-of-Speech tagging
- Syntactic Analysis
- Semantic Analysis
What does lexical ambiguity refer to?
The same word may have different meanings
What is syntactic ambiguity?
The same sentence may have different interpretations
What is semantic ambiguity?
The interpretation of a sentence may depend on its context
What is the purpose of Word Segmentation in NLP?
It divides the input text into small semantic entities (tokenisation)
What does Part-of-Speech (POS) tagging involve?
Assigning words to roles in a sentence.
i.e., classification, based on probability
What is Syntactic Analysis in NLP?
Finding the most probable grammatical interpretation of a sentence
Define Semantic Analysis.
Finding the most probable meaning of a sentence (and its words)
True or False: Traditional NLP tasks are treated independently.
False.
They depend on each other.
What is the main issue with tokenization?
Determining how to segment words and phrases correctly
Examples: possessives, hyphenated words