Rational Parsing John Hale
Phrase structure a) PP The president VB IN meets on Friday the board
4 operators PUH THE NEXT WORD W ON THE TACK PROJECT A RULE WITHOUT MATCHING (FIND A TREE) shift(w ) shiftcomplete glc(lh! TriggerRest) glccomplete(lh! TriggerRest) CAN THE WORD CURRENTLY OUGHT ON TOP OF THE TACK PROJECT A RULE AND MATCH THE OUGHT PARENT EXPECTATION
tack machine 1: procedure GLC(Grammar,Goals,Inputtring) 2: choose one of the viable GLCOptions 3: if glc (LH! Trigger Rest) then. predict without attaching 4: GLC with Trigger replaced by Rest on Goals 5: else if glcomplete (LH! Trigger Rest) then. predict and attach 6: GLC with Trigger and matching LH replaced by Rest on Goals 7: else if shift (W ) then 8: GLC with W pushed on Goals, popped from Inputtring 9: else if shiftcomplete then 10: GLC with matching W popped on Goals and popped from Inputtring 11: end if 12: end procedure
Left Corner a) The president VB meets the board IN on PP Friday hift The! [] The Glc -> The><! [] Glc -> ><! [] [] hift president! [] [] president GlcComplete -> president><! [] GlcComplete -> ><! [] hift meets! [] meets Glc VB -> meets><! [] VB Glc -> VB><! [] [] hift the! [] [] the Glc -> the><! [] [] GlcComplete -> ><! [] [] hift board! [] [] board GlcComplete -> board><! [] GlcComplete -> ><PP! [PP] hift on! [PP] on Glc IN -> on><! [PP] IN GlcComplete PP -> IN><! [] hift Friday! [] Friday GlcComplete -> Friday><!
Left Corner a) The president VB meets the board IN on PP Friday hift The! [] The Glc -> The><! [] Glc -> ><! [] [] hift president! [] [] president GlcComplete -> president><! [] GlcComplete -> ><! [] hift meets! [] meets Glc VB -> meets><! [] VB Glc -> VB><! [] [] hift the! [] [] the Glc -> the><! [] [] GlcComplete -> ><! [] [] hift board! [] [] board GlcComplete -> board><! [] GlcComplete -> ><PP! [PP] hift on! [PP] on Glc IN -> on><! [PP] IN GlcComplete PP -> IN><! [] hift Friday! [] Friday GlcComplete -> Friday><!
Expectations * 2 IP V 0 3 + 6 4 I 0 ; Vintrans; P on 7 5, [the ; floor] john I slept
/Z garden path (1) a. while Mary was mending a sock fell on the floor b. while Mary was mending, a sock fell on the floor
Phrase-structure grammar
Visited states goal state initial state dead end BAR IN while N Mary AUX was VBG mending a sock BAR IN while N Mary AUX was VBG mending a sock VBD fell PP IN on the floor
Visitation sequence BAR garden path globally-correct dead end * IN while N Mary AUX was VBG mending +, a, sock g(n) ĥ(n) f(n) 18 71 89
Informed search: A* KNOWN COT TO GET HERE FROM TART f(n) =g(n)+ĥ(n) ETIMATED VALUE OF A EARCH NODE A GUE ABOUT HOW MUCH IT LL COT TO FINIH FROM HERE
Brown corpus ĥ(n) stack contents attestations average # steps to goal standard error 55790 44.936 0.1572 53991 10.542 0.0986 43635 33.092 0.1633 38844 55.791 0.2126 34415 47.132 0.2122 33578 52.800 0.2195 PP 30693 34.454 0.1915 IN PP 27272 32.379 0.2031 22375 34.478 0.2306 AUX 16447 46.536 0.2863 VBD 16224 43.057 0.2826 VB 13548 40.404 0.3074 the 12507 34.120 0.3046 12092 43.821 0.3269 10440 66.452 0.3907
oar opportunities [A a 1 parsing strategies are pushdown transducers 0 ( 1 )A a )B b ) )C (C 3 4 (A 2 (A 5 (B ( 6 7 0 a [A b [B ] ]B 1 2 [C 3 [ 4 ]A ]C ]A 5 6 0 [B 2 b a 3 )A b 4 )B ] 5 ( ]A 6 (B ]C 7 [C )C ) [ [ ) 8 9 (a) left parser (b) right parser (c) left corner parser idea: a ^waypoint has an^input queue and ^stack P transitions as operators tune numeric prefs with RL chunk operator sequences
Read the paper Cognitive cience 35 (2011) 399 443 Copyright Ó 2010 Cognitive cience ociety, Inc. All rights reserved. IN: 0364-0213 print / 1551-6709 online DOI: 10.1111/j.1551-6709.2010.01145.x What a Rational Parser Would Do John T. Hale Department of Linguistics, Cornell University Received 4 June 2009; received in revised form 30 July 2010; accepted 31 July 2010 Talk to me! jthale@cornell.edu