Introduction to Cognitive Science Linguistics Component

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Introduction to Cognitive Science Linguistics
Component

• Lecture 2
• September 22, 2005.
• (2.00 p.m. 3.50 p.m.)
• Venue Meng Wah Complex Room 324
• Lecturer Dr. A. B. Bodomo
• Department of Linguistics
• ltabbodomo_at_hku.hkgt

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Topic 3 Formal Grammar Parsing and Generation
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Introduction

• In my previous lectures, we discussed how tacit
  linguistic knowledge can be represented at
  various levels of phonology, morphology, syntax,
  semantics, pragmatics, and their interfaces,
  including morphophonology, morphosyntax, and the
  syntax-semantics interrelationships.
• In this lecture, we shall look closely at how
  these linguistic knowledge representations can be
  formalised into an algorithm, a computational
  procedure for processing this linguistic
  knowledge.

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Keywords

• Constituent structure rules
• initial symbol
• terminal symbol
• non-terminal symbol
• generative grammar
• formal grammar

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Formal devices and notation

• The symbol ?
• indicates that a node is rewritten as or
  consists of , or has the constituents
• This is used in rewrite rules of the type
• S ? NP VP
• a sentence, S, has the constituents noun phrase
  (NP) and verb phrase (VP)
• Optionality in the grammar is expressed as X,
  Y .
• This means apply either X or Y but not both

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Formal devices and notation (contd)

• Initial symbol the symbol from which a rewrite
  rule begins (e.g. S)
• Terminal symbol the end symbols from which no
  constituent structure can be further developed
  (N, V, Art). All others are non-terminal symbols
  (e.g. NP, VP).

• The symbol is used to indicate constituent
  boundary
• e.g. _ is word initial while _ is word final
• The notation X (Y) implies that X is obligatory
  and may be followed by Y

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Two main aspects of grammatical information
processingGenerating and Parsing sentences

• Before we begin let us illustrate with a simple
  grammar and lexicon, using the following
  sentence
• The students greeted the teacher.

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The students greeted the teacher.

• Grammar
• S ? NP VP
• VP ? V NP
• NP ? Art N

• Lexicon 1
• Greeted V, - NP
• Students N
• The Art
• Teacher N

This grammar can also generate (i.e. produce)
the following sentences The teacher
greeted the students The teacher scared the
students The child ate an apple
But you have to augment i.e. increase the lexicon
as follows Lexicon2 an Art
teacher N greeted V, -NP the Art
students N scared V, -NP
apple N ate V, -NP
child N
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Sentence Generationthe algorithm

• To produce a sentence we need three things
• A set of phrase structure rules (as illustrated
  above)
• A lexicon (as illustrated above), and
• A lexical insertion rule (as explained below)
• A lexical insertion rule is an instruction to
  select the right word from a lexicon
• The following is an example of a lexical rule

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Lexical insertion rule

• For each terminal symbol of a phrase structure
  rule, select a word from the lexicon that
  satisfies the following conditions
• terminal symbol (e.g. N, V) It is a member of the
  class of
• its subcategorization frame matches that of the
  terminal symbol (e.g. V, _NP). Attach this word
  as the daughter of this terminal symbol.
• The set of rules above constitutes what is known
  as a sentence generator.

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• The whole procedure of beginning with an initial
  symbol and then working through phrase structure
  rules to adding the lexical items via lexical
  insertions rules is driven by an algorithm or a
  set of instructions.
• Let us set out an algorithm for the generation
  (production) of the sentence The students
  greeted the teacher, a grammar and a lexicon as
  follows

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The students greeted the teacher
Lexicon1 Greeted V, - NP Students N The
Art Teacher N
Grammar PS Rule (a) S ? NP VP PS Rule (b)
VP ? V NP PS Rule (c) NP ? Art N
Rule 1 Start with the initial symbol, S. Rule
2 For every non-terminal symbol, X, find a
phrase structure rule with X as left-hand symbol
and others as the right hand symbol(s), and
develop a rewrite rule with X as the mother and
the right hand symbols as ordered daughters.
Rule 3 Apply rule 2 until all branches end in
terminal symbols. Rule 4 Apply lexical rule
iteratively until every terminal symbol is
replaced by a lexical item.
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Illustrating the algorithm
Applying Rule 1
Applying Rule 2,3
Applying Rule 3
Applying Rule 4
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• From the above we can see that we have started
  from an initial string and have ended with
  terminal strings with lexical items as their
  daughters. A sentence has thus been generated
  (produced), telling us how this sentence is built
  up.
• Now, let us see how we can begin with an existing
  sentence and then break it down into its
  component parts by applying rules.

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Sentence parsing the algorithm

• To parse a sentence means to analyse it into its
  constituent parts by the systematic application
  of lexical insertion rules and some phrase
  structure rules.
• It is like the reverse process of generation.

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Types of Parsing

• Top-down Begin with the symbol S.
• Bottom-up Begin with terminal symbols (words).

Possible research Which types of parsing in
natural languages provide the most cognitively
realistic and efficient parser?
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Some sentence parsing rules which constitute a
PARSER

• For a sentence, S
• Rule 1 Determine from the lexicon the word
  class of every item and develop a partial tree
  for each word where the word class label
  dominates the word.
• Rule 2 Find a PS rule of the type X ? Y, Z and
  where the right hand symbols match some sequence
  of categories in the structure so far, and
  develop a partial tree with X as the mother and
  the right hand symbols as ordered daughters.
• Rule 3 Continue rule 2 until the root, S, is
  reached and there are no unattached strings.

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The man drank the tea.
Lexicon1 drank V, - NP man N the Art tea
N
Grammar PS Rule1 S ? NP VP PS Rule2 VP ? V
NP PS Rule3 NP ? Art N
Applying Rule 1
Applying Rule 2
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Applying Rule 3
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Conclusion

• Parsing and generation of natural language data
  is a very important area of linguistics,
  especially in computer applications of natural
  languages which has become an important aspect of
  the computer or information processing industry.

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Topic 4 Language and Literacy Acquisition
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Keywords

• language acquisition
• innateness hypothesis
• language faculty / Language Acquisition Device
  (LAD)
• literacy
• levels of literacy
• literacy acquisition

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Introduction

• Theme
• A survey of how linguistic knowledge is
  acquired/learnt by speakers of a language, from
  the point of view of spoken language and from the
  point of view of literacy (reading and writing).
• Objective
• an understanding of the basic terms and issues in
  language and literacy acquisition
• an interface approach rather than rigidly
  discussing these issues from language acquisition
  as separate and different from literacy
  acquisition, we will look at how language
  acquisition relates to literacy acquisition.

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What is language acquisition?

• Gleitman and Bloom 1999434
• refers to the process of attaining a specific
  variant of human languagethe fundamental puzzle
  in understanding this process has to do with the
  open-ended nature of what is learned children
  appropriately use words acquired in one context
  to make reference in the next, and they construct
  novel sentences to make known their changing
  thoughts and desires (in MIT Encyclopedia of the
  Cognitive Sciences).

• Crystal 1997 430
• The process of learning a first language in
  children.
• The analogous process of gaining a foreign or
  second language.

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Explaining how languages are acquired

• In previous lectures we have tried to account for
  how all and only the grammatical sentences of a
  language are produced and represented in the
  brain of the speakers of a language.
• However, a complete account of linguistic
  knowledge representation must address the issue
  of how we acquire a language as children and how
  we learn foreign languages as adults.
• We will mainly be concerned with first language
  acquisition and not foreign language learning.

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Stages of language development

• the single word stage (12-18 months)
• the language of the child consists of just a few
  isolated words of the target language, e.g.
  mamma, daddy,etc.
• very little grammatical development
• the grammar stage (19-29 months)
• marked by the emergence of a few nominal and
  verbal inflections in languages that have these.
• a few phrases and word utterances apparently
  strung together mammy, milk daddy bye bye,
  etc.
• 30 months
• can produce more adult-like speech Where's
  daddy ? Daddy, I want to go with you.

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Explaining language acquisition

• The reason for the uniformity and rapidity in
  child language acquisition is contained in the
  innateness hypothesis.
• This is, at least, the position of Chomsky and
  most cognitive approaches to linguistic
  explanation.
• In this hypothesis, language acquisition is
  determined by a biologically endowed innate
  language faculty (also called Language
  Acquisition Device (LAD)).
• LAD or language learning program in childrens
  brains provides them with a set of procedures
  (let us call it an algorithm since we are
  computer/cognitive science inclined) for
  developing a grammar.
• Input linguistic experience they get from the
  parents and teachers.

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The nature of the language faculty

• Children can acquire any language as their native
  tongue.
• e.g. a child of Cantonese speaking parents
  growing up in England can learn to speak perfect
  English as her native tongue.
• Those aspects of language innately determined are
  universal
• language faculty does not vary significantly from
  human to human

An important aspect in the language faculty is
the search for principles of Universal Grammar!
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Universal Grammar (UG)

• A theory of the human language faculty, i.e. a
  module of the mind/brain involved in the basic
  design of language (Noam Chomsky)
• It is part of an innate biologically endowed
  language faculty, an innate mental organ specific
  to the human species
• It allows us to perceive and interpret
  information governed by certain formal
  constraints
• These formal constraints refer to a system of
  rules and representations and one of its
  operations (its grammar) by which the acceptable
  sentences of a language can be generated
• Examples of formal universals, linguistic
  constraints of an abstract nature the binding
  principles determining what can or cannot be the
  antecedent of an anaphoric, pronominal, or fully
  referential nominal element, etc.

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Literacy Acquisition

• Literacy the ability to read, write and
  calculate basic numbers
• Difficult to define
• can mean different things to different people in
  different areas computer literacy, investment
  literacy, etc.
• Is literacy part of our mental, cognitive
  faculty?
• Yes, because any human can acquire literacy i.e.
  learn how to read, write and calculate basic
  numbers given the right environment

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Levels of Literacy (cf. Stages of language
acquisition)

• 6 stages of reading (Daswani 1999)
• Stages 1-3 Pre-reading, decoding, fluency
  (approx. grades 1 3)
• Stage 4 Acquiring new knowledge (approx.grades 4
  8)
• Stage 5 Reading a range of complex materials
  critically (grades 9 12)
• Stage 6 Mature reader able to read for various
  purposes professional, personal, civic
  (university and beyond)

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The relationship between language and literacy
acquisition

• Traditional/historical view of child language
  acquisition
• learning to speak happens up to the age of five
  years, while learning to read happens after five.
• Now they are seen as very intertwined i.e. very
  related learning to speak and learning to be
  literate both deal with learning to use language
• the basis of learning to speak has been outlined
  to provide an ecology for literacy. The most
  important lesson is that learning to speak and
  learning to read are very much interwoven.

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Evidence of the interface of language and
literacy acquisition

• They are both part of learning to USE language.
• Both need input from the environment.
• can be compared with Vygotsky's idea of ZOPED,
  zone of proximal development, i.e. the distance
  between child initiative and ability of child to
  do things under the influence of parental
  support.
• The learning environment participants,
  situation, activity and a mechanism
• Literacy acquisition is like language acquisition
  (cf. Givon's idea of literacy acquisition as a
  weak reflex of language acquisition).
• Literacy is best acquired in a language one has
  acquired.

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Conclusion

• Literacy (reading and writing) is then another
  level/kind of linguistic knowledge
  representation.
• Spoken and written linguistic knowledge
  representation interface with each other and are
  very intertwined.
• Language and literacy acquisition have very
  important social, educational and cognitive
  implications.
• Language and Literacy acquisition should
  therefore form an integral part of cognitive
  science.

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References

• David Barton. 1994. The roots of literacy.
  Literacy An Introduction to the Ecology of
  Written Language. Oxford UK and Cambridge USA
  Blackwell. Chapter 9, p.130-139.
• C. J. Daswani. 1999. Literacy. In Bernard Spolsky
  (ed) 1999. Concise Encyclopedia of Educational
  Linguistics. Oxford Elsevier Science Ltd..
• Viv Edwards and David Corson (eds.) 1997.
  Encyclopedia of Language and Education, Volume 2
  Literacy. Netherlands Kluwer Academic
  Publishers.
• Talmy Givon. 1998. The grammar of Literacy. In
  Syntaxis, 1, 1998 1-40.
• Elfrieda Hierbert. 1994. Literacy in preschool
  programs. In Alan C. Purves et al.(eds.) 1994.
  Encyclopedia of English Studies and Language
  Arts. New York Scholastic. 754-756.
• Ernest Lepore and Zenon Pylyshyn (eds). 1999.
  What Is Cognitive Science. Blackwell Publishers.
  (especially chapters 10, 11, 12, and 13)
• Neil Stillings and others. 1995. Cognitive
  Science An Introduction. MIT Press. (especially
  chapters 6, 9, 10, and 11)
• Daniel A. Wagner. 1994. Literacy definitions. In
  Alan C. Purves et al.(eds.) 1994. Encyclopedia of
  English Studies and Language Arts. New York
  Scholastic. 748-752.
• R. Wilson and Frank C. Neil (eds.) 1999. The MIT
  Encyclopedia of the Cognitive Sciences. MIT
  Press.
• Lila Gleitman and Paul Bloom. Language
  Acquisition. p.434-438
• David Olson. Literacy. p.481-482

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Tentative List of research topics for Cognitive
Science Students

• Supervisor Dr. Adams BODOMO (abbodomo_at_hku.hk)
• Topics in Syntax Theory, Description and
  Application
• Building human language components in
  Computational Systems
• The LFG treatment of serial verbs, Complex
  Predicates, and other verbal constructions in
  various languages French, Norwegian, Japanese,
  Chinese, Dagaare, etc
• Topics in Language and Literacy as cognitive
  processes
• Chinese writing and computer technology Survey
  and evaluation of various inputting systems.
• New forms and functions of language and literacy
  in the age of Information technology (emails,
  ICQ, bulletin boards, mobile phone
  texting,etc).A survey of SMS texting as a
  cognitive and communicative process in HK
• The grammar of aphasic patients

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Further studies - courses by Dr Bodomo

• LING1002 - Language.com Language in the
  Contemporary World (1st year undergraduate,
  co-taught with other staff members)
• LING2011 - Language and Literacy in the
  Information Age
• LING2032 - Syntactic Theory
• LING2018 - Lexical-Functional Grammar
• LING2041 - Language and Information Technology
• LING2050 Grammatical Description
• LING2051 French Syntax and Universal Grammar
• Also consider B.A. in Human Language Technology
  (HLT) as an option for a minor

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Take-home Quiz

• Please submit your answers to your tutor on or
  before September 22, 2005.

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- The End -