a modern
approach
input
sentence
morphological
processing
lexicon
syntax
analysis
(parsing)
grammar
semantic
rules
contextual
information
semantic
analysis
pragmatic
analysis
target
representation
step 1- morphological processing
objective: strip words into roots & modifiers
issues
• inflection
• derivation
(cat pl  cat-s)
(happy adj  happiness noun)
• compounding
(toothpaste)
step 2- syntax analysis
objectives: 1 check for correctness
2 produce phrase structure
uses
• parser
• grammar
• lexicon
a rule-based search engine
context-free production rules
dictionary of words & their categories
semantic processing (one approach)
• semantic rules in grammar  1st stage case frame
• verb form  primitive action case frame
•
•
•
•
•
disambiguate & fill additional case frame slots
check references with world and/or dialog
do statement level inference
integrate with dialog
do event sequence dialog
the ambiguity problem
eg: the boy kicked the ball under the tree
grammar rules
S  S PP
S  NP VP
NP  ?det *adj noun
NP  NP PP
step-1: produce raw case frame
• verb cases
the cat chased the rat in the kitchen
the cat chased the rat into the kitchen
the boy kicked the bal / wall under the tree
• common cases
source
destination
location
start-time
end-time
duration
instrument
beneficiary
semantics in grammar rules
(s1 (s ->
(actor
(action
(object
*.pp
)
np vp *pp)
. np)
. vp.action)
. vp.object)
(vp (vp -> verb np)
(action . verb)
(object . np)
)
(np (np -> det noun ?pp)
(det . noun)
pp
)
(pp (pp -> prep np)
(prep . np)
)
example frame #1
actor
(quant specific)
(tags animate male human)
(qual (age (range 3 13)))
(root boy)
action (root kick)
object (root ball)
(tags manip)
(posn-relative
(locator beneath)
(object (root tree)
...etc... )
example frame #2
actor
(quant specific)
(tags animate male human)
(qual (age (range 3 13)))
(root boy)
action (root kick)
object (root ball)
(tags manip)
dest
(posn-relative
(locator beneath)
(object (root tree)
...etc... )
example verb form #1
primitive
strike
prohibited
object (tags manip)
slots
instrument (part-of $actor foot)
legal
start-time, end-time, duration
instrument, beneficiary, location
illegal
source, dest
example verb form #2
primitive
push
required
object (tags manip)
slots
instrument (part-of $actor foot)
legal
source, dest, start-time, end-time,
instr, beneficiary, locatn, duration
semantic processing (one approach)
× semantic rules in grammar  1st stage case frame
× verb form  primitive action case frame
× disambiguate & fill additional case frame slots
check references with world and/or dialog
do statement level inference
• integrate with dialog
• do event sequence dialog
integration with dialog
dialogs have...
• players (actors)
• props (objects)
• locations (from case frames)
• themes (derived)
• event sequences (from themes)
• plans (from themes and/or derived)
event sequence
set of...
• players (actors)
• props (objects)
series of...
• semantically encoded activities (matched)
• escapes, exceptions & alternatives