Probabilistic algorithms … …
III. Chomsky‟s Criticisms

Criticism of induction/generalization Criticism of analogy
Chomsky: „analogy‟ wrong
(1) John is easy to please (2) John is eager to please They are similar, so the child should interpret them analogously. But the child does not do this. So the idea of analogy is wrong.
The child would do:
the man who is tall is in the room — is the man who tall is in the room?
But the child actually does:
the man who is tall is in the room — is the man who is tall in the room?
Heart of these criticisms



Proponents of analogy or generalization might say that the child does not make those analogies or generalizations But they cannot say exactly when analogy/generalization should be or should not be made Without this, theory of analogy/generalization is empty

Specified Subject Constraint
* [CP [IP Johni appears [CP [IP it is likely [IP ti to win] ________________________ Can now be explained as: John moved across two bounding nodes (IP nodes)

WH-Island Constraint
I sometimes wonder [why she is popular] *[CP Populari, [IP I sometimes wonder [CPwhy [IP she is ti]]]]. ____________________________________ Can now be explained as: popular moved across two bounding nodes (IP nodes)
V. Chomsky‟s Research Methods

Galileo（伽利略）style of inquiry

Do not consider all data Concentrate on some interesting data Make simplifications

E.g. assume there is vacuum E.g. Free-fall
Chomsky’s Philosophy of language
Outline
I. Descartes vs. Locke
Rationalism vs. Empiricism
II. Empiricist‟s theory of language III. Chomsky‟s criticisms IV. Chomsky‟s rationalist theory of language V. Chomsky‟s research methods
Chomsky: other learning theories are also wrong

Similar criticisms
IV. Chomsky‟s Rationalist Theory of Language



The child does not make such mistakes It shows that the child has grammatical knowledge that is not learned by analogy or generalisation This knowledge consists of innate grammatical rules or principles This knowledge is Universal Grammar (UG) （普遍语法）

Build a precise model to explain these data


Recalcitrant （顽抗的）data may be explained later

E.g. a feather does not abide Law of Free Fall But can be explained
The above few rules are then generalized into Subjacency
Principles and Parameters （原理和 参数）to explain language variation

UG consists of a list of abstract principles Each principle is associated with a paramThere are no innate ideas All knowledge comes from experience All knowledge are based on simple ideas and complex ideas The mind has some abilities to
II. Empiricist‟s Theory of Language

Knowledge of language is learned There are some general learning mechanisms


Induction/Generalization （归纳/推衍） Analogy （类比） Harris‟s “discovery procedures” （乔姆斯基博士导 师） Other learning algorithms (人工智能领域的）

Complex NP Constraint
[CP Whati did [IP John claim [CP that [IPMary owns ti]]]]? _________________________________ [CP *Whati did [IP John make [NP the claim [CP that [IPMary owns ti]]]]? _________________________________________________

E.g. a grammatical sentence that violates Subjancency may be explained by other means
Chomsky: „generalisation‟ wrong
(1) John ate an apple. (2) John ate. (3) John is too stubborn to talk to Bill. (4) John is too stubborn to talk to. Generalising from (1) and (2): (5) Whenever an object is missing, an arbitrary object is meant. But if the child applies (5) to (4), it will get a wrong interpretation But the child does not make such a mistake.


When the child is placed in a language environment, the linguistic input will set the parameters to some values

E.g. head-first or head-second rose red or red rose （rose is the head 中心词）
I. Descartes vs. Locke

Descartes

Language distinguishes humans from animals There are innate ideas

Clear and distinct ideas

I think, therefore I am God exists mathematics Geometry … Maybe also knowledge of language??
In different language environments, parameters will be set to different values So, a child in different language environments will acquire different grammars


Perceive Compare Remember Abstract …

Stimulus + Sense organs + mind‟s abilities knowledge Knowledge of language also obtained in this way??