Midterm Review

1
Midterm Review

• CS4705
• Natural Language Processing

2
Midterm Review

• Statistical v. Symbolic Processing
• 80/20 Rule
• Regular Expressions
• Finite State Automata
• Determinism v. non-determinism
• (Weighted) Finite State Transducers
• Morphology
• Word Classes
• Inflectional v. Derivational
• Affixation, infixation, concatenation
• Morphotactics

3

• Morphological parsing
• Koskenniemis two-level morphology
• Porter stemmer
• Minimum Edit Distance (Levenshtein)
• N-grams
• Markov assumption
• Chain Rule
• Language Modeling
• Simple, Adaptive, Class-based (syntax-based),
  bursty
• Smoothing
• Add-one, Witten-Bell, Good-Turing
• Back-off
• Perplexity, Entropy
• Maximum Likelihood Estimation

4

• Syntax
• Chomskys view Syntax is cognitive reality
• Parse Trees
• Dependency Structure
• Part-of-Speech Tagging
• Hand Written Rules v. Statistical v. Hybrid
• Brill Tagging
• Types of Ambiguity
• Context Free Grammars
• Top-down v. Bottom-up Derivations
• Left Corners
• Grammar Equivalence
• Normal Forms (CNF)

5

• Probabilistic Parsing
• (p)CYK, Earley Parsing
• Derivational Probability
• Lexicalization
• Classification
• Supertagging
• Machine Learning
• Dependent v. Independent variables
• Training v. Development Test v. Test sets
• Feature Vectors
• Metrics
• Accuracy
• Precision, Recall, F-Measure
• Gold Standards

6

• Semantics
• Meaning Representations
• Semantic Roles, Subcategorization frames
• FOPC
• Pros
• Cons
• Temporal Representations
• Richenbach
• Aspect
• Beliefs, Desires, Intention Representation
• Syntax-driven semantics