CS 182 Sections 101 102

1
CS 182Sections 101 - 102

• Klinton Bicknell (kbicknell at berkeley dot
  edu
• April 20, 2005

2
Announcements

• a8 due today by midnight
• a9 out sometime tomorrow (last one!)
• Hows your progress on the BBS articles?
• Highly suggest you start this early! there is a
  dead week, so use your time wisely!
• Ideas for open lecture? We really want to hear
  from you! Might be an application lecture?

3
Schedule

• Last Week
• SHRUTI
• Formal Grammar and Parsing
• This Week
• Construction Grammar, ECG
• Language Learning
• Next Week
• Learning ECG
• Psychological model of sentence processing

4
Quiz

• What are constructions?
• What is the difference between subcasing and
  evoking another schema or construction?
• How does the analyzer use the constructions to
  parse a sentence?
• What does SHRUTI buy us?
• How are bindings propagated in a structured
  connectionist framework?

5
Quiz

• What are constructions?
• What is the difference between subcasing and
  evoking another schema or construction?
• How does the analyzer use the constructions to
  parse a sentence?
• What does SHRUTI buy us?
• How are bindings propagated in a structured
  connectionist framework?

6
Embodied constructions
ECG Notation
Form
Meaning
Harry
cafe
Constructions have form and meaning poles that
are subject to type constraints.
7
Quiz

• What are constructions?
• What is the difference between subcasing and
  evoking another schema or construction?
• How does the analyzer use the constructions to
  parse a sentence?
• What does SHRUTI buy us?
• How are bindings propagated in a structured
  connectionist framework?

8
A schema hierarchy of objects (Nomi)
slot filler
9
The schemas we just defined
Entity
Place
Object
Referent
Physical-Object
Animate
Manipulable-Object
Food
Human
Toy
Cup
Cake
Juice
Nomi
Mother
Father
Book
Ball
Block
Doll
Bed
10
A schema hierarchy of actions (Nomi)
type constraint
identification constraint
11
The schemas we just defined
Action
Directed Action
Move
Cause-Move
JointMove
Transfer
12
Constructions, finally (Nomi)
local name
fancy way of saying that the category of the
referent is Nomi
13
Constructions, finally (Nomi)
lexical construction
14
Constructions, finally (Nomi)
smaller constructions that it takes
ordering constraints on the constituents
15
Quiz

• What are constructions?
• What is the difference between subcasing and
  evoking another schema or construction?
• How does the analyzer use the constructions to
  parse a sentence?
• What does SHRUTI buy us?
• How are bindings propagated in a structured
  connectionist framework?

16
I will get the cup

• the analyzer allows the skipping of unknown
  lexical items
• here is the SemSpec

Remember that the transitive construction takes 3
constituents? agt Ref-Expr v
Cause-Motion-Verb obj Ref-Expr their meaning
poles are agt Referent v CauseMove obj
Referent
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I will get the cup

• the analyzer allows the skipping of unknown
  lexical items
• here is the SemsSpec

Remember that the transitive construction takes 3
constituents? agt Ref-Expr v
Cause-Motion-Verb obj Ref-Expr their meaning
poles are agt Referent v CauseMove obj
Referent
18
Analyzer Chart
Chart Entry 0 Construct0 (I-Cn) span 0,
0 processed input I Meaning
SCHEMA5 Construct94 (Transitive-Cn) span 0,
2 processed input I get cup Meaning
SCHEMA57 Chart Entry 1 Construct7
(Get-Cn) span 1, 1 processed input
get Meaning SCHEMA10 Chart Entry
2 Construct23 (Cup-Cn) span 2, 2 processed
input cup Meaning SCHEMA27

• 3 lexical constructions are recognized
• The transitive construction is recognzied and
  spans all three words

19
Analyzing in ECG

• create a recognizer for each construction in the
  grammar
• for each level j (in ascending order)
• repeat
• for each recognizer r in j
• for each position p of utterance
• initiate r starting at p
• until the number of states in the chart doesn't
  change

20
Recognizer for the Transitive-Cn

• an example of a level-1 construction is
  Red-Ball-Cn
• each recognizer looks for its constituents in
  order (the ordering constraints on the
  constituents can be a partial ordering)

21
Quiz

• What are constructions?
• What is the difference between subcasing and
  evoking another schema or construction?
• How does the analyzer use the constructions to
  parse a sentence?
• What does SHRUTI buy us?
• How are bindings propagated in a structured
  connectionist framework?

22
SHRUTI

• A connectionist model of reflexive processing

23
SHRUTI

• synchronous activity without using global clock
• An episode of reflexive processing is a transient
  propagation of rhythmic activity
• An entity is a phase in the above rhythmic
  activity.
• Bindings are synchronous firings of role and
  entity cells
• Rules are interconnection patterns mediated by
  coincidence detector circuits that allow
  selective propagation of activity
• Long-term memories are coincidence and
  coincidence-failure detector circuits
• An affirmative answer / explanation corresponds
  to reverberatory activity around closed loops

24
focal cluster

• provides locus of coordination, control and
  decision making
• enforce sequencing and concurrency
• initiate information seeking actions
• initiate evaluation of conditions
• initiate conditional actions
• link to other schemas, knowledge structures

25
Quiz

• What are constructions?
• What is the difference between subcasing and
  evoking another schema or construction?
• How does the analyzer use the constructions to
  parse a sentence?
• What does SHRUTI buy us?
• How are bindings propagated in a structured
  connectionist framework?

26
dynamic binding example

• asserting that get(father, cup)
• father fires in phase with agent role
• cup fires in phase with patient role

my-father
entity
cup
type
get
?
predicate
27
Active Schemas in SHRUTI

• active schemas require control and coordination,
  dynamic role binding and parameter setting
• schemas are interconnected networks of focal
  clusters
• bindings are encoded and propagated using
  temporal synchrony
• scalar parameters are encoded using rate-encoding

28
Representing constructions TO
local alias
identification constraint
The meaning pole may evoke schemas (e.g., image
schemas) with a local alias. The meaning pole may
include constraints on the schemas (e.g.,
identification constraints ?).
29
The INTO construction
TO vs. INTO INTO adds a Container schema and
appropriate bindings.
30
Constructions with constituentsThe
SPATIAL-PHRASE construction
local alias
order constraint
identification constraint
31
An argument structure construction
32
The CAUSED-MOTION construction