1. Studying learning
1.1 An overview of grammatical inference
1.2 Formal and empirical grammatical inference
1.3 Formal grammatical inference
1.3.1 Language and grammar
1.3.2 Language families
1.3.3 Learning languages efficiently
1.4 Empirical grammatical inference
1.4.1 Languages, grammars, and language families
1.4.2 Evaluation
1.5 Summary
1.6 Formal preliminaries
2. Formal learning
2.1 Introduction
2.1.1 The issues of learning
2.1.2 Learning scenarios
2.1.3 Learning grammars of languages
2.2 Learnability: definitions and paradigms
2.2.1 Blame the data, not the algorithm
2.2.2 A non-probabilistic setting: identification in the limit
2.2.3 An active learning setting
2.2.4 Introducing complexity
2.2.5 A probabilistic version of identification in the limit
2.2.6 Probably approximately correct (PAC) learning
2.3 Grammar formalisms
2.3.1 Finite-state machines recognizing strings
2.3.2 Probabilistic finite-state machines
2.3.3 Transducers
2.3.4 More complex formalisms
2.3.5 Dealing with trees and graphs
2.4 Is grammatical inference an instance of machine learning?
2.5 Summary
3. Learning regular languages
3.1 Introduction
3.2 Bias selection reduces the problem space
3.3 Regular grammars
3.4 State-merging algorithms
3.4.1 The problem of learning stress patterns
3.4.2 Merging states
3.4.3 Finite-state representations of finite samples
3.4.4 The state-merging theorem
3.5 State-merging as a learning bias
3.6 State-merging as inference rules
3.7 RPNI
3.7.1 How it works
3.7.2 Theoretical results
3.8 Regular relations
3.9 Learning stochastic regular languages
3.9.1 Stochastic languages
3.9.2 Structure of the class is deterministic and known a priori
3.9.3 Structure of the class is deterministic but not known a priori
3.9.4 Structure of the class is non-deterministic and not known a priori
3.10 Summary
4. Learning non-regular languages
4.1 Substitutability
4.1.1 Identifying structure
4.1.2 Learning using substitutability
4.2 Empirical approaches
4.2.1 Expanding and reducing approaches
4.2.2 Supervised and unsupervised approaches
4.2.3 Word-based and POS-based approaches
4.2.4 Description of empirical systems
4.2.5 Comparison of empirical systems
4.3 Issues for evaluation
4.3.1 Looks-good-to-me approach
4.3.2 Rebuilding known grammars
4.3.3 Compare against a treebank
4.3.4 Language membership
4.4 Formal approaches
4.5 Summary
5. Lessons learned and open problems
5.1 Summary
5.2 Lessons
5.3 Problems
5.3.1 Learning targets
5.3.2 Learning criteria
5.4 Resources
5.5 Final words
Bibliography
Author biographies.