Sunday, June 24, 2012

The Minimalist Program

Everyone speaks language. If people do not have a speech impediment, they acquire their native languages without any difficulties, regardless of his or her parents mother tongue. This fact implies that human beings have certain inborn and general abilities of acquiring any languages. The long-standing question was how we explain the process. Noam Chomsky, a MIT linguist, came up with the concept of how our language processing works.

Language faculty is composed of cognitive system and performance system
Chomsky argues that language faculty is composed of cognitive system and performance system. Cognitive system stores information, and performance system accesses to information and uses it. Performance system and cognitive system interact through two interfaces: the two systems interact each other by using phonetic form (utterance) of language through articulatory perceptual system, and using logical form (meaning) through conceptual intentional system.

According to Chomsky, performance system does not vary in the manner of the cognitive system, i.e. the system is universal and does not change by the selection of languages. Thus, his study mainly focuses on the cognitive system.

Chomsky says that cognitive system consists of a computational system and a lexicon. The computational system generates form of structural description, i.e. sound (phonetic form) and meaning (logical form) of an object. The lexicon is a repository of all properties of particular lexical items, specifying the elements that the computational system selects and integrates to form linquistic expressions, i.e. phonetic form and logical form. (see the diagram below)



In Chomskys terminology, acquiring a language is equivalent to acquiring generative grammar. When one acquire languages, one is able to conduct infinitive use of finite means, i.e. once we acquire languages, the generative grammar allows us to generate any sentences regardless of our experiences and thus to rule out the ungrammatical language expressions.


Universal Grammar, P&P model, and the Minimalist Program
According to Chomsky, there is universal grammar (UG) by which we acquire any languages. UG is something common to all human speeches and an invariant system of human speech principles. The UG hypothesis explains why all human beings can acquire their native languages regardless of their parents mother tongue.

Using UG, Chomsky proposed Principles & Parameters (P&P) model, which argues that our languages are composed of very simple principles (UG) and parameters, and the choice of parameters determines the differences among various languages. Let us quote what he says to understand it more deeply:

Language acquisition is interpreted as the process of fixing the parameters of the initial state in one of the permissible ways (Minimalist Program, page 6). A language is not, then, a system of rules, but a set of specifications for parameters in an invariant system of principles of UG (page 129).

The concept of relationship between UG and language acquisition has evolved as Chomsky develops his theory, and by the end of 20th century, he proposed the idea of the Minimalist Program. In the minimalist program, he argues that derivation (computation) and representation of languages are subject to a certain form of least effort (minimalist approach) condition and are required to be minimal in a fair well-defined sense. That is, the computation and representation process of human speech generally takes most efficient way, ruling out redundancy in language processing. Chomsky calls it the most economical convergent derivation (page 201).  According to the minimalist program approach, lexicon of cognitive system specifies the information that is optimal and non-redundant.



Remarks
This was the first time for me to read an orthodox linguistics book, and this book is so far the most challenging book among what I have read since this year (actually, this book could be more readable one). As always, it is the greatest pleasure to tackle a new concept and understand it, thus acquiring the new perspective to see the world. (I hope I understand his theory correctly in general sense) By introducing the concept of UG, P&P model and the minimalist program, Chomsky made it far clear to understand the variety of human languages.

I also would like to quote what Chomsky noted in question shaping. The remark is full of insights.

Typically, when questions are more sharply formulated, it is learned that even elementary phenomena had escaped notice, and that intuitive accounts that seemed simple and persuasive are entirely inadequate. If we are satisfied that an apple falls to the ground because that is its natural place, there will be no serious science of mechanics. The same is true if one is satisfied with traditional rules for forming questions, or with the lexical entries in the most elaborate dictionaries, none of which come close to describing simple properties of these linguistic objects.


Reference
Noam Chomsky, The Minimalist Program, The MIT Press, 1995/9/28

Saturday, June 02, 2012

The Science of the Artificial


Harbert Simon, a professor of computer science and psychology as well as the 1978 Nobel laureate in Economics, pursued the “artificial science”, or knowledge about artificial objects and phenomena. According to him, artificial things have the following characteristics which distinguish themselves from natural:

- Artificial things are synthesized (though not always or usually with full forethought) by human beings
- Artificial things may imitate appearances in natural things while lacking in one or many respects, the reality of the latter
- Artificial things can be characterized in terms of functions, goals, adaptation
- Artificial things are often discussed, particularly when they are being designed, in terms of imperatives as well as descriptives


Human being as a simple system
Simon began with human beings. After studying aspects of imperfect problem solving activities of human beings and the other artifacts (i.e. computers), he claimed that human beings are quite simple. He said, “The apparent complexity of our behavior over time is largely a reflection of the complexity of the environment in which we find ourselves.” (page 53) What makes our behaviors complex is information of the situations full of variety. If we use metaphor to describe the problem solving activities of human beings, we can say as follows: human being is like a simple function having variables in it, and information is input to the variables.

There are some facts showing the very limited ability of human being. According to a study of Dansereau and Gregg, the times required for elementary arithmetic operations and for fixation of intermediate results account for only part of the total time for performing mental multiplications of four digits by two. Much of the remaining time appears to be devoted to retrieving numbers from the memory where they have been fixated. The fact suggests that the system of human beings is basically serial in its operation, i.e. we can solve the problems only through “one-by-one” style.

This simplicity of human being is counter-intuitive. However, Simon says to this notion that “Only human pride argues that the apparent intricacies of our path stem from a quite different source than the intricacy of the ant’s path.”


Science of designing artificial
Based on the studies of human beings’ behavior, Simon turns to the design of artificial. Although not comprehensive, he proposes the following evaluation criteria of artificial design:
1) Theory of evaluation: the artifacts act to maximize utility, or they could make decision based on statistic
2) Computational methods: (a) algorithms for choosing optimal alternatives such as linear programming computations, control theory, dynamic programming; (b) algorithms and heuristics for choosing satisfactory alternatives
3) The formal logic of design: imperative and declarative logics
4) The search for alternatives: (a) heuristic search; (b) allocation of resources for search
5) Theory of structure and design organization
6) Representation of design problems (the definition of the problems)


Curriculum for social design
He also discusses about the aspects we need to pay attention in social planning:
1) bounded rationality: the meaning of rationality can be quite complex if we think about the rationality in complex situations
2) Data for planning: the social system needs methods of forecasting, the use of prediction and feedback in control
3) Identifying the client: we need to think about for whom we create the system
4) Organizations in social design: an important goal of the design is to fashion and change social organization in general and individual organizations in particular
5) Time and space horizons
6) Designing without final goals: it means the system needs to be designed as an evolving system, full of flexibility for future uncertainties


Remarks
It is outstanding to think about the system and human being in this way at the time when this book was published. The hardest task is to deny the complexity of human behaviors, and the out-of-the-box thinking enabled the author to come up with his idea.

Although the studies in this book seem very scattered to me, the study of unknown fields always tends to be like that, through out the history of the progress of theories: when the first thesis appears, it takes very complex methodology to solve problems, but as the theory evolves, there will be more formalized, simple and beautiful methodology.


Reference
Harbert A. Simon, “The Science of the Artificial” (3rd edition), The MIT Press, 1996/10/1)