cva-ccs.ppt - PowerPoint PPT Presentation

About This Presentation
Title:

cva-ccs.ppt

Description:

cva-ccs.ppt version: 20090126 Contextual Vocabulary Acquisition: From Algorithm to Curriculum William J. Rapaport* and Michael W. Kibby** (*)Department of Computer ... – PowerPoint PPT presentation

Number of Views:62
Avg rating:3.0/5.0
Slides: 46
Provided by: CSEDepa
Learn more at: https://cse.buffalo.edu
Category:
Tags: ccs | cva | philosophy | ppt | science

less

Transcript and Presenter's Notes

Title: cva-ccs.ppt


1
cva-ccs.ppt
  • version 20090126

2
Contextual Vocabulary AcquisitionFrom Algorithm
to Curriculum
  • William J. Rapaport and Michael W. Kibby
  • ()Department of Computer Science Engineering,
  • Department of Philosophy, Department of
    Linguistics,
  • and Center for Cognitive Science
  • ()Department of Learning Instruction
  • and Center for Literacy Reading Instruction
  • http//www.cse.buffalo.edu/rapaport/CVA/

3
Research Foci
  • Learning andthe Lexicon

4
Research Focus
  • Learningthe Lexicon

5
Research Focus
  • Learningthe Lexicon
  • Not primarily child language acquisition
  • Adolescent adult language expansion
  • 2nd-language acquisition

6
Contextual Vocabulary Acquisition
  • Active, conscious acquisition of a meaning for a
    word,as it occurs in a text, by reasoning from
    context
  • CVA what you do when
  • Youre reading
  • You come to an unfamiliar word
  • Its important for understanding the passage
  • No ones around to ask
  • Dictionary doesnt help
  • So, you figure out a meaning for the word from
    context
  • figure out infer (compute) a hypothesis
    about what the word might mean in that
    text
  • context ??

7
What Does Brachet Mean?(From Malorys Morte
DArthur page in brackets)
  • 1. There came a white hart running into the
    hall with a white brachet next to him, and thirty
    couples of black hounds came running after them.
    66
  • As the hart went by the sideboard,the white
    brachet bit him. 66
  • The knight arose, took up the brachet androde
    away with the brachet. 66
  • A lady came in and cried aloud to King
    Arthur,Sire, the brachet is mine. 66
  • There was the white brachet which bayed at him
    fast. 72
  • 18. The hart lay dead a brachet was biting on
    his throat,and other hounds came behind. 86

8
Why Dictionaries Dont Help
  • Most words are learned via incidental CVA, not
    via dictionaries
  • Incidental (unconscious) CVA is best explanation
    of how we learn vocabulary
  • Given of words high-school grad knows (45K),
    of years to learn them (18) 2.5K words/year
  • But only taught 10 in 12 school years
  • Most importantly
  • Dictionary definitions are just more contexts!

9
  • Why Not Use a Dictionary?
  • Most words are learned via incidental CVA
  • not via dictionaries
  • Dictionaries are not always available
  • People are lazy (!)
  • Dictionaries are always incomplete
  • Dictionary definitions are not always useful
  • chaste def sexually pure clean, spotless
    ? new dishes are chaste
  • college def a body of clergy living together
    and supported by a foundation
  • Most importantly
  • Dictionary definitions are just more contexts!

10
Why not use a dictionary?
  • Merriam-Webster New Collegiate Dictionary
  • chaste.
  • innocent of unlawful sexual intercourse
  • student stay away from that one!
  • celibate
  • student huh?
  • pure in thought and act modest
  • student I have to find a sentence for that?
  • a severely simple in design or execution
    austere
  • student huh? severely? austere?
  • b clean, spotless
  • student all right! The plates were still
    chaste after much use.
  • Deese 1967 / Miller 1985

11
Why not use a dictionary?
  • Merriam-Webster (continued)
  • college.
  • a body of clergy living together and supported by
    a foundation
  • a building used for an educational or religious
    purpose
  • a a self-governing constituent body of a
  • university offering living quarters and
  • instruction but not granting degrees
  • b a preparatory or high school
  • c an independent institution of higher
  • learning offering a course of general
  • studies leading to a bachelors
    degree
  • Problem ordering is historical!

12
Why not use a dictionary?
  • Merriam-Webster (continued)
  • infract infringe
  • infringe encroach
  • encroach
  • to enter by gradual steps or by stealth into the
    possessions or rights of another
  • to advance beyond the usual or proper limits
    trespass

13
Why not use a dictionary?
  • Collins COBUILD Dictionary
  • Helping Learners with Real English
  • chaste.
  • Someone who is chaste does not have sex with
    anyone, or only has sex with their husband or
    wife an old-fashioned use, used showing
    approval. EG She was a holy woman, innocent and
    chaste.
  • Something that is chaste is very simple in style,
    without much decoration. EG chaste houses built
    in 1732

14
Why not use a dictionary?
  • Collins COBUILD Dictionary
  • college.
  • A college is 1.1 an institution where students
    study for qualifications or do training courses
    after they have left school.
  • infract not in dictionary
  • infringe.
  • If you infringe a law or an agreement, you break
    it.
  • encroach.
  • To encroach on or upon something means to slowly
    take possession or control of it, so that someone
    else loses it bit by bit.

15
What Is the Context for CVA?
  • context ? textual context
  • surrounding words co-text of word
  • context wide context
  • internalized co-text
  • readers interpretive mental model of textual
    co-text
  • integrated with readers prior knowledge
  • world knowledge
  • language knowledge
  • previous hypotheses about words meaning
  • but not including external sources (dictionary,
    humans)
  • via belief revision
  • infer new beliefs from internalized co-text
    prior knowledge
  • remove inconsistent beliefs
  • ? Context for CVA is in readers mind, not in
    the text

16
Prior Knowledge
Text
PK1 PK2 PK3 PK4
17
Prior Knowledge
Text
T1
PK1 PK2 PK3 PK4
18
Integrated KB
Text
T1
internalization
PK1 PK2 PK3 PK4
I(T1)
19
B-R Integrated KB
Text
T1
internalization
PK1 PK2 PK3 PK4
I(T1)
inference
P5
20
B-R Integrated KB
Text
T1
internalization
PK1 PK2 PK3 PK4
I(T1)
T2
inference
P5
I(T2)
P6
21
B-R Integrated KB
Text
T1
internalization
PK1 PK2 PK3 PK4
I(T1)
T2
inference
T3
P5
I(T2)
P6
I(T3)
22
B-R Integrated KB
Text
T1
internalization
PK1 PK2 PK3 PK4
I(T1)
T2
inference
T3
P5
I(T2)
P6
I(T3)
23
Note All contextual reasoning is done in this
context
B-R Integrated KB (the readers mind)
Text
T1
internalization
PK1 PK2 PK3 PK4
P7
I(T1)
T2
inference
T3
P5
I(T2)
P6
I(T3)
24
Meaning of Meaning
  • the meaning of a word vs. a meaning for a
    word
  • the ? single, correct meaning
  • of ? meaning belongs to word
  • a ? many possible meanings depending on
    textual context,
  • readers prior knowledge, etc.
  • for ? reader hypothesizes meaning from
    context, gives it to word

25
  • The meaning of things lies not in themselves
    but in our attitudes toward them.
  • Antoine de Saint-Exupéry, Wisdom of the Sands
    (1948)
  • Words dont have meaning theyre cues to
    meaning!Words might be better understood as
    operators, entities that operate directly on
    mental states in what can be formally understood
    as a dynamical system.
  • Jeffrey L. Elman, On Words and Dinosaur Bones
    Where Is Meaning? (2007)
  • We cannot locate meaning in the text
    figuring out meaning is an active, dynamic
    process, existing only in interactive behaviors
    of cultural, social, biological, and physical
    environment-systems.
  • William J. Clancey, Scientific Antecedents of
    Situated Cognition (forthcoming)

26
State of the Art Computational Linguistics
  • Information extraction systems
  • Autonomous intelligent agents
  • There can be no complete lexicon
  • Such systems/agents shouldnt have to stop to ask
    questions

27
State of the Art Computational Linguistics
  • Granger 1977 Foul-Up
  • Based on Schanks theory of scripts (schema
    theory)
  • Our system not restricted to scripts
  • Zernik 1987 self-extending phrasal lexicon
  • Uses human informant
  • Ours system is really self-extending
  • Hastings 1994 Camille
  • Maps unknown word to known concept in ontology
  • Our system can learn new concepts
  • Word-Sense Disambiguation
  • Given ambiguous word list of all
    meanings,determine the correct meaning
  • Multiple-choice test -)
  • Our system given new word, compute its meaning
  • Essay question -)

28
State of the Art Vocabulary Learning (I)
  • Elshout-Mohr/van Daalen-Kapteijns 1981,1987
  • Application of Winstons AI arch learning
    theory
  • (Good) readers model of new word frame
  • Attribute slots, default values
  • Revision by updating slots values
  • Poor readers update by replacing entire frames
  • But EM vDK used
  • Made-up words
  • Carefully constructed contexts
  • Presented in a specific order

29
Elshout-Mohr van Daalen-Kapteijns
  • Experiments with neologisms in 5 artificial
    contexts
  • When you are used to a view it is depressing when
    you live in a room with kolpers.
  • Superordinate information
  • At home he had to work by artificial light
    because of those kolpers.
  • During a heat wave, people want kolpers, so
    sun-blind sales increase.
  • Contexts showing 2 differences from the
    superordinate
  • I was afraid the room might have kolpers, but
    plenty of sunlight came into it.
  • This house has kolpers all summer until the
    leaves fall out.
  • Contexts showing 2 counterexamples due to the 2
    differences

30
State of the Art Psychology
  • Johnson-Laird 1987
  • Word understanding ? definition
  • Definitions arent stored
  • During the Renaissance, Bernini cast a bronze of
    a mastiff eating truffles.

31
State of the Art Psychology
  • Sternberg et al. 1983,1987
  • Cues to look for ( slots for frame)
  • Spatiotemporal cues
  • Value cues
  • Properties
  • Functions
  • Cause/enablement information
  • Class memberships
  • Synonyms/antonyms
  • To acquire new words from context
  • Distinguish relevant/irrelevant information
  • Selectively combine relevant information
  • Compare this information with previous beliefs

32
Sternberg
  • The couple there on the blind date was not
    enjoying the festivities in the least. An
    acapnotic, he disliked her smoking and when he
    removed his hat, she, who preferred ageless
    men, eyed his increasing phalacrosis and
    grimaced.

33
Overview of CVA Project
  • From Algorithm
  • Implemented computational theory of how tofigure
    out (compute) a meaning for an unfamiliar
    wordfrom wide context
  • to Curriculum
  • Convert algorithms to an improved, teachable
    curriculum

34
CVA as Philosophical Computation
  • Origin of project
  • Rapaport, How to Make the World Fit Our
    Language (1981)
  • (Intensional) theory of a words meaning for a
    personas the set of contexts in which person has
    heard or seen word.
  • Could that notion be made precise?
  • Semantic-network theory offered a computational
    tool
  • Developed into Karen Ehrlichs CS Ph.D.
    dissertation (1995)
  • Later, learned that computational
    linguists,reading educators, L2 educators,
    psychologists,were all interested in this
  • A really interdisciplinary cognitive-science
    problem

35
1. Computational CVA
  • Implemented in SNePS (Shapiro 1979 Shapiro
    Rapaport 1992)
  • Intensional, propositional, semantic-networkknowl
    edge-representation, reasoning, acting system
  • intensional
  • e.g., can represent fictional objects
  • propositional
  • can represent sentences in a text
  • semantic network
  • labeled, directed graph with nodes linked by arcs
  • indexed by node
  • from any node, can describe rest of network
  • Serves as model of the reader (Cassie)

36
1. Computational CVA (contd)
  • KB SNePS representation of readers prior
    knowledge
  • I/P SNePS representation of word in its
    co-text
  • Processing (simulates/models/is?! reading)
  • Uses logical inference, generalized inheritance,
    belief revisionto reason about text integrated
    with readers prior knowledge
  • N V definition algorithms deductively search
    this belief-revised, integrated KB (the wide
    context) for slot fillers for definition frame
  • O/P Definition frame
  • slots (features) classes, structure, actions,
    properties, etc.
  • fillers (values) info gleaned from context (
    integrated KB)

37
Cassie learns what brachet meansBackground
info about harts, animals, King Arthur, etc.
world kn.No info about brachetsInput forma
l-language (SNePS) version of simplified
EnglishA hart runs into King Arthurs hall.
In the story, B12 is a hart. In the story, B13
is a hall. In the story, B13 is King
Arthurs. In the story, B12 runs into B13.A
white brachet is next to the hart. In the
story, B14 is a brachet. In the story, B14 has
the property white. Therefore, brachets are
physical objects. (deduced while reading
Cassies PK only physical objects have color)
38
--gt (defineNoun "brachet") Definition of
brachet Class Inclusions phys obj, Possible
Properties white, Possibly Similar Items
animal, mammal, deer, horse, pony, dog,
I.e., a brachet is a physical object that can be
white and that might be like an animal,
mammal, deer, horse, pony, or dog
39
A hart runs into King Arthurs hall.A white
brachet is next to the hart.The brachet bites
the harts buttock. PK Only animals
bite--gt (defineNoun "brachet") Definition of
brachet Class Inclusions animal, Possible
Actions bite buttock, Possible Properties
white, Possibly Similar Items mammal, pony,
40
A hart runs into King Arthurs hall. A white
brachet is next to the hart. The brachet bites
the harts buttock. The knight picks up the
brachet. The knight carries the brachet. PK
Only small things can be picked up/carried --gt
(defineNoun "brachet") Definition of brachet
Class Inclusions animal, Possible Actions
bite buttock, Possible Properties small,
white, Possibly Similar Items mammal, pony,
41
A hart runs into King Arthurs hall.A white
brachet is next to the hart.The brachet bites
the harts buttock.The knight picks up the
brachet.The knight carries the brachet.The lady
says that she wants the brachet. PK Only
valuable things are wanted--gt (defineNoun
"brachet") Definition of brachet Class
Inclusions animal, Possible Actions bite
buttock, Possible Properties valuable, small,
white, Possibly Similar Items mammal,
pony,
42
  • A hart runs into King Arthurs hall.A white
    brachet is next to the hart.The brachet bites
    the harts buttock.The knight picks up the
    brachet.The knight carries the brachet.The lady
    says that she wants the brachet.
  • The brachet bays at Sir Tor. PK Only hunting
    dogs bay
  • --gt (defineNoun "brachet")
  • Definition of brachet
  • Class Inclusions hound, dog,
  • Possible Actions bite buttock, bay, hunt,
  • Possible Properties valuable, small, white,
  • I.e. A brachet is a hound (a kind of dog) that
    can bite, bay, and hunt,
  • and that may be valuable, small, and white.

43
General Comments
  • Cassies behavior ? human protocols
  • Cassies definition ? OEDs definition
  • A brachet is a kind of hound which hunts by
    scent

44
Fragment of readers prior knowledge m3 In
real life, white is a color
Member(Lex(white),Lex(color),LIFE) m6 In
real life, harts are deer
AKO(Lex(hart),Lex(deer),LIFE) m8 In real
life, deer are mammals
AKO(Lex(deer),Lex(mammal),LIFE) m11 In real
life, halls are buildings
AKO(Lex(hall),Lex(building),LIFE) m12 In real
life, b1 is named King Arthur
Name(b1,King Arthur,LIFE) m14 In real life,
b1 is a king Isa(ISA,b1,Lex(king),LIFE)
(etc.)
45
m16 if v3 has property v2 v2 is a color v3
? v1 then v1 is a class of physical
objects all(x,y,z)(Is1(z,y),Member1(y,lex(color))
,Member1(z,x) gt
AKO1(x,lex(physical object)))
46
Reading the story m17 In the story, b2 is a
hart ISA(b2,lex(hart),STORY) m24 In
the story, the hart runs into b3 Does(b2,into(b3,
lex(run)),STORY) (b3 is King Arthurs hall) not
shown (harts are deer) not shown
47
  • A fragment of the entire network,
  • showing the readers mental context consisting
    of
  • prior knowledge, the story, inferences.
  • The definition algorithm
  • searches this entire network,
  • abstracts parts of it,
  • produces a hypothesized meaning for
    brachet.

48
Algorithms (for Computers)
  • Generate initial hypothesis bysyntactic
    manipulation
  • Algebra Solve an equation for unknown value X
  • Syntax Solve a sentence for unknown word X
  • A white brachet (X) is next to the hart? X (a
    brachet) is something that is next to the hart
    and that can be white.
  • I.e., define node X in terms of immediately
    connected nodes
  • Deductively search wide context to update
    hypothesis
  • I.e., define word X in terms of some (but not
    all) other connected nodes
  • Return definition frame.

49
Noun Algorithm
  • Generate initial hypothesis by syntactic
    manipulation
  • Then find or infer from wide context
  • Basic-level class memberships (e.g., dog,
    rather than animal)
  • else most-specific-level class memberships
  • else names of individuals
  • Properties of Xs (else, of individual Xs) (e.g.,
    size, color, )
  • Structure of Xs (else ) (part-whole, physical
    structure)
  • Acts that Xs perform (else ) or that can be done
    to/with Xs
  • Agents that do things to/with Xs
  • or to whom things can be done with Xs
  • or that own Xs
  • Possible synonyms, antonyms

50
Verb Algorithm
  • Generate initial hypothesis by syntactic
    manipulation
  • Then find or infer from wide context
  • Class membership (e.g., Conceptual Dependency)
  • What kind of act is X-ing (e.g., walking is a
    kind of moving)
  • What kinds of acts are X-ings (e.g., sauntering
    is a kind of walking)
  • Properties/manners of X-ing (e.g., moving by
    foot, slow walking)
  • Transitivity/subcategorization information
  • Return class membership of agent, object,
    indirect object, instrument
  • Possible synonyms, antonyms
  • Causes effects
  • Also preliminary work on adjective/adverb
    algorithm

51
Belief Revision
  • To revise definitions of words used
    inconsistently with current meaning hypothesis
  • SNeBR (ATMS Martins Shapiro 1988, Johnson
    2006)
  • If inference leads to a contradiction, then
  • SNeBR asks user to remove culprit(s)
  • automatically removes consequences inferred
    from culprit

52
Revision Expansion
  • Removal revision being automated via SNePSwD by
    ranking all propositions with kn_cat
  • most intrinsic info re language fundamental
    background info
  • certain (before is transitive)
  • story info in text (King Lot rode
    to town)
  • life background info w/o variables or
    inference
  • (dogs are animals)
  • story-comp info inferred from text (King
    Lot is a king, rode on a horse)
  • life-rule.1 everyday commonsense
    background info
  • (BearsLiveYoung(x) ? Mammal(x))
  • life-rule.2 specialized background info
  • (x smites y ? x kills y by
    hitting y)
  • least
  • certain questionable already-revised
    life-rule.2 not part of input

53
Belief Revision smite
  • Misunderstood word
  • Initially believe that smite meanskill by
    hitting
  • Read King Lot smote down King Arthur
  • Infer that King Arthur is dead
  • Then read King Arthur drew his sword Excalibur
  • Contradiction!
  • Weaken definition to hit and possibly kill
  • Then read more passages in which smiting ?gt
    killing
  • Hypothesize that smite means hit

54
Belief Revision smite
  • Misunderstood word 2-stage subtractive
    revision
  • Background knowledge includes
  • () smite(x,y,t) ? hit(x,y,t) dead(y,t)
    cause(hit(x,y,t),dead(y,t))
  • P1 King Lot smote down King Arthur
  • D1 If person x smites person y at time t, then x
    hits y at t, and y is dead at t
  • Q1 What properties does King Arthur have?
  • R1 King Arthur is dead.
  • P2 King Arthur drew Excalibur.
  • Q2 When did King Arthur do this?
  • SNeBR is invoked
  • KAs drawing E is inconsistent with being dead
  • () replaced smite(x,y,t) ? hit(x,y,t)
    ?dead(y,t) dead(y,t) ? cause(hit, dead)
  • D2 If person x smites person y at time t, then
    x hits y at t ?(y is dead at t)
  • P3 another passage in which (smiting ?
    death)
  • D3 If person x smites person y at time t, then
    x hits y at t

55
Belief Revision to dress
  • Well-entrenched word
  • Believe to dress means to put clothes on
  • Commonsense belief
  • Spears dont wear clothing
  • used in new sense
  • Read King Claudius dressed his spear
  • Infer that spear wears clothing
  • Contradiction!
  • Modify definition to to put clothes on OR to do
    something else
  • Read King Arthur dressed his troops before
    battle
  • Infer that dress means to put clothes on OR
    to prepare for battle
  • Eventually Induce more general definition
  • to prepare (for the day, for battle, for
    eating)

56
Belief Revision dress
  • additive revision
  • Background info includes
  • dresses(x,y) ? ?zclothing(z) wears(y,z)
  • Spears dont wear clothing (both
    kn_catlife.rule.1)
  • P1 King Arthur dressed himself.
  • D1 A person can dress itself result it wears
    clothing.
  • P2 King Claudius dressed his spear.
  • Cassie infers King Claudiuss spear wears
    clothing.
  • Q2 What wears clothing?
  • SNeBR is invoked
  • KCs spear wears clothing inconsistent with (2).
  • (1) replaced dresses(x,y) ? ?zclothing(z)
    wears(y,z) v NEWDEF
  • Replace (1), not (2), because of verb in
    antecedent of (1) (Gentner)
  • P3 other passages in which dressing spears
    precedes fighting
  • D2 A person can dress a spear or a person
  • result person wears clothing or person
    is enabled to fight

57
A Computational Theory of CVA
  • A word does not have a unique meaning.
  • A word does not have a correct meaning.
  • Authors intended meaning for word doesnt need
    to be known by readerin order for reader to
    understand word in context
  • Even familiar/well-known words can acquire new
    meanings in new contexts.
  • Neologisms are usually learned only from context
  • Every co-text can give some clue to a meaning for
    a word.
  • Generate initial hypothesis via
    syntactic/algebraic manipulation
  • But co-text must be integrated with readers
    prior knowledge
  • Large co-text large PK ? more clues
  • Lots of occurrences of word allow asymptotic
    approach to stable meaning hypothesis
  • CVA is computable
  • CVA is open-ended, hypothesis generation.
  • CVA ? guess missing word (cloze) ? CVA ?
    word-sense disambiguation
  • Some words are easier to compute meanings for
    than others (N lt V lt Adj/Adv)
  • CVA can improve general reading comprehension
    (through active reasoning)
  • CVA can should be taught in schools

58
2. From Algorithm to Curriculum
  • State of the art in classroom CVA
  • not good
  • e.g., Clarke Nation 1980 a strategy
    (algorithm?)
  • Determine part of speech of word
  • Look at grammatical context
  • Who does what to whom?
  • Look at surrounding textual context
  • Search for clues (as we do)
  • Guess the word check your guess

59
CVA From Algorithm to Curriculum
  • guess the word
  • then a miracle occurs
  • Surely, computer scientists
  • can be more explicit!
  • And so should teachers!

60
From Algorithm to Curriculum (contd)
  • We have explicit, rule-based (symbolic) AI theory
    of CVA
  • ? Teachable!
  • Goal
  • Not teach people to think like computers
  • But explicate computable teachable
    methods to hypothesize word meanings from
    context
  • AI as computational psychology
  • Devise computer programs that faithfully
    simulate(human) cognition
  • Can tell us something about (human) mind
  • Joint work with Michael Kibby (UB Reading Clinic)
  • We are teaching a machine, to see if what we
    learn in teaching it can help us teach students
    better

61
Contextual Semantic Investigation (CSI)A
Curriculum Outline
  1. Teacher models CSI
  2. Teacher models CSI with student participation
  3. Students model CSI with teacher assistance
  4. Students do CSI in small groups
  5. Students do CSI on their own

62
CSI Algorithms (for Humans)
  • Become aware of word X of need to understand X
  • Repeat
  • Generate hypothesis H about Xs meaning
  • Test H
  • until H is a plausible meaning for X in
    the current wide context

63
IIB. Test H
  1. Replace all occurrences of X in sentence by H
  2. If Sentence (X H) makes sense then proceed
    with reading else generate new H

64
IIA. Generate H
  • Make an intuitive guess H
  • If H fails or you cant guess, then do in any
    order
  • if you have you read X before if you
    (vaguely) recall its meaning, then test
    that earlier meaning
  • if you can generate a meaning from Xs
    morphology, then test that meaning
  • if you can make an educated guess (next
    slide), then test it

65
IIA. Generate H
  • Do in any order to generate H
  • Make an intuitive guess
  • Try to recall Xs meaning from previous reading
  • Use Xs morphology
  • Make an educated guess

66
IIA1d Make an Educated Guess
  1. Re-read Xs sentence slowly actively
  2. Determine Xs part of speech
  3. Summarize entire text so far
  4. Activate your PK about the topic
  5. Make inferences from text PK
  6. Generate H based on all this

67
IIA2 If all previous steps fail,then do CVA
  1. Solve for X
  2. Search context for clues
  3. Create H

68
IIA2a Solve for X
  1. Syntactically manipulate Xs sentenceso that X
    is the subject
  2. Generate a list of possible synonyms(as
    hypotheses in waiting)

69
IIA2aii Generate a list of hypotheses in
waiting
  • Sandra had won the dance contest the
    audiences cheers brought her to the stage for an
    encore. Every step she takes is so perfect
    graceful, Ginny said grudgingly, as she watched
    Sandra dance. (Beck, McKeown, McCaslin 1983)
  • A misdirective context?
  • But syntactic manipulation yields
  • Grudgingly is a way of
  • saying something (e.g., quickly, loudly,)
  • praising someones performance (lavishly,
    honestly)
  • apparently praising (e.g., ironically,
    sarcastically, reluctantly)

70
IIA2b Search context for clues
  • If X is a noun, then search context for clues
    about Xs
  • class membership
  • properties
  • structure
  • acts
  • agents
  • comparisons
  • contrasts

71
IIA2b Search context for clues
  • If X is a verb, then search context for clues
    about Xs
  • class membership
  • what kind of act Xing is
  • what kinds of acts are Xings
  • properties of Xing (e.g., manner)
  • transitivity
  • look for agents and objects of Xing
  • cause effect information
  • comparisons contrasts

72
IIA2b Search context for clues
  • If X is an adjective or adverb, then search
    context for clues about Xs
  • class membership
  • is it a color adjective, a size adjective, a
    shape adjective, etc.?
  • contrasts
  • is it an opposite or complement of something else
    mentioned?
  • parallels
  • is it one of several otherwise similar modifiers
    in the sentence?

73
IIA2c Create H
  • Aristotelian definitions
  • What kind of thing is X?
  • How does it differ from other things of that
    kind?
  • Schwartz Raphael definition map
  • What is X?
  • What is it like?
  • What are some examples?
  • Express (important parts of) definition
    framein a single sentence
  • Cf. Collins COBUILD

74
Computation Philosophy
  • Computational philosophy
  • Application of computational (i.e., algorithmic)
    solutionsto philosophical problems
  • Philosophical computation
  • Application of philosophy to CS problems

75
CVA as Computational Philosophy
  • CVA holistic semantic theories
  • Semantic networks
  • Meaning of a node is its location in the entire
    network
  • Holism
  • Meaning of a word is its relationships to all
    other words in the language
  • Problems (Fodor Lepore)
  • No 2 people ever share a belief
  • No 2 people ever mean the same thing
  • No 1 person ever means the same thing at
    different times
  • No one can ever change his/her mind
  • Nothing can be contradicted
  • Nothing can be translated
  • CVA offers principled way to restrict entire
    networkto a useful subnetwork
  • That subnetwork can be shared across people,
    individuals, languages,
  • Can also account for language/concept change
  • Via dynamic/incremental semantics

76
  • Searles CR argument from semantics
  • Computer programs are purely syntactic
  • Cognition is semantic
  • Syntax alone does not suffice for semantics
  • No purely syntactic computer program can exhibit
    semantic cognition
  • How would Searle-in-the-Room figure out the
    meaning of an unknown squiggle?
  • By CVA techniques!
  • Syntactic Semantics (Rapaport 1985ff)
  • Syntax does suffice for the kind of semantics
    needed for NLU in the CR
  • All inputlinguistic, perceptual, etc.is encoded
    in a single network(or in a single, real
    neural network the brain!)
  • Relationsincluding semantic onesamong nodes of
    such a networkare manipulated syntactically
  • Hence computationally (CVA helps make this
    precise)

77
CVA Searles CRA
  • Computer programs are purely syntactic.
  • Cognition is semantic.
  • Syntax alone does not suffice for semantics.
  • No purely syntactic computer program can exhibit
    semantic cognition.
  • How would Searle-in-the-room figure out a
    meaning for an unknown squiggle?
  • By CVA!
  • Syntactic Semantics (Rapaport 1985ff)
  • Syntax does suffice for the kind of semantics
    needed for NLU in the CR
  • All inputlinguistic, perceptual, etc.is encoded
    in a single LOT
  • or in a single neural network the brain!
  • Relationsincluding semantic onesamong terms of
    such a LOT are manipulated syntactically
  • hence computationally (CVA helps make this
    precise)

78
CVA as Cognitive Science
  • AI
  • knowledge representation
  • reasoning
  • natural-language understanding
  • acting(?)
  • Philosophy
  • Linguistics
  • Psychology
  • Reading
  • Education

79
To Do
  • More examples (over 50 so far)
  • More experiments with prior knowledge
  • Eye-tracking investigation???
  • Nature of abductive(?) general PK rules
  • Better search algorithms
  • Improve belief-revision component
  • Class-test the curriculum
  • Karen Wieland _at_ U/Pitt
Write a Comment
User Comments (0)
About PowerShow.com