Such systems extract information from some types of syntactic units ( clauses in ( Fillmore and Atkins , 1998 ; Gildea and Jurafsky , 2002 ; Hull and Gomez , 1996 ) ; noun phrases in ( Hull and Gomez , 1996 ; Rosario et al. , 2002 ) ) .


`` petty conversational implicature '' ( Hobbs 1979 ) , or the metarules of Section 5.2 ?


Unlike other POS taggers , this POS tagger ( Mikheev 2000 ) was also trained to disambiguate sentence boundaries .


On the other hand , experiments indicate that mental representation and processing of morphologically complex words are not quite language independent ( Taft , 2004 ) .


ASARES has been previously applied to the acquisition of word pairs sharing semantic relations defined in the Generative Lexicon framework ( Pustejovsky , 1995 ) and called qualia relations ( Bouillon et al. , 2001 ) .


People are much more likely to consult such evaluative statements than the actual text of a bill or law under discussion , given the dense nature of legislative language and the fact that ( U.S. ) bills often reach several hundred pages in length ( Smith et al. , 2005 ) .


For english , there is for instance the 15 year old HewlettPackard test suite , a simple text file listing test sentences and grouping them according to linguistics phenomena ( Flickinger et al. , 1987 ) ; and more recently , the much more sophisticated TSNLP ( Test Suite for Natural Language Processing ) which includes some 9500 test items for English , French and German , each of them being annotated with syntactic and application related information ( Oepen and Flickinger , 1998 ) .


Its significance is reflected both in the growing interest in annotation software for word sense tagging ( Edmonds and Kilgarriff , 2002 ) and in the long-standing use of part-of-speech taggers , parsers and morphological analysers for data from English and many other languages .


Each of these Values has equal status , so the notion of a basic-level Value can not play a role ( cfXXX , Dale and Reiter 1995 ) .


Previous work on Chinese SRL mainly focused on how to transplant the machine learning methods which has been successful with English , such as Sun and Jurafsky ( 2004 ) , Xue and Palmer ( 2005 ) and Xue ( 2008 ) .


Accuracy is not the best measure to assess segmentation quality , therefore we also conducted experiments using the WindowDiff measure as proposed by Pevzner and Hearst ( 2002 ) .


The system is in the form of an agenda-driven chart-based parser whose foundation is similar to previous formalizations of Chomsky 's Minimalist Program ( Stabler , 1997 ; Harkema , 2000 ; Niyogi , 2001 ) .


Optimizing for dependency arc length is particularly important as parsers tend to do worse on longer dependencies ( McDonald and Nivre , 2007 ) and these dependencies are typically the most meaningful for downstream tasks , e.g. , main verb dependencies for tasks


Whereas Rapp & Zock ( 2010 ) dealt only with an English corpus , the current work shows that this methodology is applicable to a wide range of languages and corpora .


We also experiment with a CCG parser ( Clark and Curran , 2007 ) , requiring that the contexts surrounding the original phrase and paraphrase are assigned


Their kernel is also very time consuming and in their more general sparse setting it requires O ( mn3 ) time and O ( mn2 ) space , where m and n are the number of nodes of the two trees ( m > = n ) ( Zelenko et al. , 2003 ) .


Other molecular biology databases We also included several model organism databases or nomenclature databases in the construction of the dictionary , i.e. , mouse Mouse Genome Database ( MGD ) [ 18 ] , fly FlyBase [ 19 ] , yeast Saccharomyces Genome Database ( SGD ) [ 20 ] , rat -- Rat Genome Database ( RGD ) [ 21 ] , worm -- WormBase [ 22 ] , Human Nomenclature Database ( HUGO ) [ 23 ] , Online Mendelian Inheritance in Man ( OMIM ) [ 24 ] , and Enzyme Nomenclature Database ( ECNUM ) [ 25 , 26 ] .


ones , DIRT ( Lin and Pantel , 2001 ) , VerbOcean ( Chklovski and Pantel , 2004 ) , FrameNet ( Baker et al. , 1998 ) , and Wikipedia ( Mehdad et al. , 2010 ; Kouylekov et al. , 2009 ) .


include decision tree learning and Bayesian learning , nearest neighbor learning , and artificial neural networks , early such works may be found in ( Lewis and Ringnette , 1994 ) , ( Creecy and Masand , 1992 ) and ( Wiene and Pedersen , 1995 ) , respectively .


In other words AJAX is a web development technique for creating interactive web applications using a combination of XHTML and CSS , Document Object Model ( or DOM ) , the XMLHTTPRequest object ( Wikipedia , 2005 ) .


For these or for a specific domain , basic synonymic dictionaries can be complemented using learning methods based on distributional similarity ( Pereira et al. , 1993 ; Lin , 1998 ) .


converted to numerical features using the standard technique of binarization , and we split values of the FEATS field into its atomic components .4 For some languages , we divide the training data into smaller sets , based on some feature s ( normally the CPOS or POS of the next input token ) , which may reduce training times without a significant loss in accuracy ( Yamada and Matsumoto , 2003 ) .


â¢ language learning ( Green 1979 ; Mori and Moeser 1983 ; Morgan , Meier , and Newport 1989 ) â¢ monolingual grammar induction ( Juola 1998 ) â¢ grammar optimization ( Juola 1994 ) â¢ insights into universal grammar ( Juola 1998 ) â¢ machine translation ( Juola 1994 , 1997 ; Veale and Way 1997 ; Gough , Way , and Hearne 2002 )


Linguistic preprocessing of text documents is carried out by re-using smes , an information extraction core system for real-world German text processing ( Neumann et al. , 1997 ) .


Regarding future work , there are many research line that may be followed : i ) Capturing more features by employing external knowledge such as ontological , lexical resource or WordNet-based features ( Basili et al. , 2005a ; Basili et al. , 2005b ; Bloehdorn et al. , 2006 ; Bloehdorn and Moschitti , 2007 ) or shallow semantic trees , ( Giuglea and Moschitti , 2004 ; Giuglea and Moschitti , 2006 ; Moschitti and Bejan , 2004 ; Moschitti et al. , 2007 ; Moschitti , 2008 ; Moschitti et al. , 2008 ) .


For English â > Urdu , Juola ( 1997 , page 213 ) notes that `` the system learned the original training corpus ... perfectly and could reproduce it without errors '' ; that is , it scored 100 % accuracy when tested against the training corpus .


Much previous work looks at the impact of using source side information ( i.e. , feature functions on the aligned English ) , such as those of Avramidis and Koehn ( 2008 ) , Yeniterzi and Oflazer ( 2010 ) and others .


Recent work ( Banko and Brill , 2001 ; Curran and Moens , 2002 ) has suggested that some tasks will benefit from using significantly more data .


See Nederhof ( 1998 ) for a variant of this approximation that constructs finite transducers rather than finite automata .


Due to their remarkable ability to incorporate context structure information and long distance reordering into the translation process , tree-based translation models have shown promising progress in improving translation quality ( Liu et al. , 2006 , 2009 ; Quirk et al. , 2005 ; Galley et al. , 2004 , 2006 ; Marcu et al. , 2006 ; Shen et al. , 2008 ; Zhang et al. , 2011b ) .


These include devices such as interleaving the components ( McDonald 1983 ; Appelt 1983 ) , backtracking on failure ( Appelt 1985 ; Nogier 1989 ) , allowing the linguistic component to interrogate the planner ( Mann 1983 ; Sondheimer and Nebel 1986 ) , and Hovy 's notion of restrictive ( i.e. , bottom-up ) planning ( Hovy 1988a , 1988c ) .


The shallow parser used is the SNoW-based CSCL parser ( Punyakanok and Roth , 2001 ; Munoz et al. , 1999 ) .


Other approaches use less deep linguistic resources ( e.g. , POS-tags Stymne ( 2008 ) ) or are ( almost ) knowledge-free ( e.g. , Koehn and Knight ( 2003 ) ) .


Some well-known approaches include rule-based models ( Brill and Resnik 1994 ) , backed-off models ( Collins and Brooks 1995 ) , and a maximumentropy model ( Ratnaparkhi 1998 ) .


One approach to partial parsing was presented by Buchholz et al. ( 1999 ) , who extended a shallow-parsing technique to partial parsing .


Soricut and Brill ( 2006 ) compared a predictive approach ( statistical translation ) , a retrieval approach based on a language-model , and a hybrid approach which combines statistical chunking and traditional retrieval .


Indeed , such rich semantic links can be used to extend indices or reformulate queries ( similar to the work by Voorhees ( 1994 ) with WoRDNET relations ) .


In modern syntactic theories ( e.g. , lexical-functional grammar [ LFG ] [ Kaplan and Bresnan 1982 ; Bresnan 2001 ; Dalrymple 2001 ] , head-driven phrase structure grammar [ HPSG ] [ Pollard and Sag 1994 ] , tree-adjoining grammar [ TAG ] [ Joshi 1988 ] , and combinatory categorial grammar [ CCG ] [ Ades and Steedman 1982 ] ) , the lexicon is the central repository for much morphological , syntactic , and semantic information .


Despite these arguments , most applied NLG systems use a pipelined architecture ; indeed , a pipeline was used in every one of the systems surveyed by Reiter ( 1994 ) and Paiva ( 1998 ) .


Other similar approaches include those of Cicekli and G Â¨ uvenir ( 1996 ) , McTait and Trujillo ( 1999 ) , Carl ( 1999 ) , and Brown ( 2000 ) , inter alia .


The EDR has close ties to the named entity recognition ( NER ) and coreference resolution tasks , which have been the focus of several recent investigations ( Bikel et al. , 1997 ; Miller et al. , 1998 ; Borthwick , 1999 ; Mikheev et al. , 1999 ; Soon et al. , 2001 ; Ng and Cardie , 2002 ; Florian et al. , 2004 ) , and have been at the center of evaluations such as : MUC-6 , MUC-7 , and the CoNLL '02 and CoNLL '03 shared tasks .


In addition to headwords , dictionary search through the pronunciation field is available ; Carter ( 1987 ) has merged information from the pronunciation and hyphenation fields , creating an enhanced phonological representation which allows access to entries by broad phonetic class and syllable structure ( Huttenlocher and Zue , 1983 ) .


Following Hockenmaier , Bierner , and Baldridge ( 2002 ) , Xia ( 1999 ) , and Miyao , Ninomiya , and Tsujii ( 2004 ) , we extract a reference lexicon from Sections 02 -- 21 of the WSJ .


The only disambiguation metric that we used in our previous work ( Marcu , 1997b ) was the shape-based metric , according to which the `` best '' trees are those that are skewed to the right .


The need for information systems to support physicians at the point of care has been well studied ( Covell et al. , 1985 ; Gorman et al. , 1994 ; Ely et al. , 2005 ) .


Every arc always has a definite direction , i.e. arcs are arrows ( Novak , 1998 ) .


In the first experiment , we use an induction algorithm ( Hwa 2001a ) based on the expectation-maximization ( EM ) principle that induces parsers for PLTIGs .


To create the baseline system , we use the opensource Joshua 4.0 system ( Ganitkevitch et al. , 2012 ) to build a hierarchical phrase-based ( HPB ) system , and a syntax-augmented MT ( SAMT ) 11 system ( Zollmann and Venugopal , 2006 ) respectively .


6 For Sent-Pred we also experimented with grammatical and sentence-based syntactic features , such as number of syntactic phrases , grammatical mood , and grammatical person ( Marom and Zukerman 2006 ) , but the simple binary bag-of-lemmas representation yielded similar results .


At present , the system uses a heuristic matching algorithm to classify relations into the appropriate category , though in the future we may consider a classifier similar to Nielsen et al. ( 2008 ) .


It is interesting to compare this analysis with that described in Dalrymple , Shieber , and Pereira ( 1991 ) and Pereira ( 1990 , 1991 ) .


The importance of including nonheadwords has become uncontroversial ( e.g. Collins 1999 ; Charniak 2000 ; Goodman 1998 ) .


Some methods of semantic relation analysis rely on predefined templates filled with information from processed texts ( Baker et al. , 1998 ) .


The example used to illustrate the power of ATNs ( Woods 1986 ) , `` John was believed to have been shot , '' also parses correctly , because the [ object ] node following the verb `` believed '' acts as both an absorber and a ( re ) generator .


Problems such as these have motivated research on more abstract , dependencybased parser evaluation ( e.g. , Lin 1995 ; Carroll , Briscoe , and Sanfilippo 1998 ; Carroll et al. 2002 ; Clark and Hockenmaier 2002 ; King et al. 2003 ; Preiss 2003 ; Kaplan et al. 2004 ; Miyao and Tsujii 2004 ) .


LiLFeS is one of the fastest inference engines for processing feature structure logic , and efficient HPSG parsers have already been built on this system ( Nishida et al. , 1999 ; Torisawa et al. , 2000 ) .


As in ( Lee et al. , 2003 ) , we used unsupervised training data which is automatically segmented to discover previously unseen stems .


To address this limitation , our previous work ( Zhang and Chai , 2009 ) has initiated an investigation on the problem of conversation entailment .


â A brief version of this work , with some additional material , first appeared as ( Eisner , 2001a ) .


They also proposed two major categories of meta-learning approaches for recommender systems , merging and ensemble , each subdivided into the more specific subclasses suggested by Burke ( 2002 ) as follows .


Here , I adopt the model proposed by Marantz ( 1997 ) and decompose lexical verbs into verbalizing heads and verbal roots .


This heuristic is called soft union ( DeNero and Klein 2007 ) .


This approach has its roots in Fillmore 's Case Grammar ( 1968 ) , and serves as the foundation for two current large-scale semantic annotation projects : FrameNet ( Baker et al. , 1998 ) and PropBank ( Kingsbury et al. , 2002 ) .


Many investigators ( e.g. Allen 1976 ; Elowitz et al. 1976 ; Luce et al. 1983 ; Cahn 1988 ) have suggested that the poor prosody of synthetic speech , in comparison with natural speech , is the primary factor leading to difficulties in the comprehension of fluent synthetic speech .


The ability to explicitly identify these sections in unstructured text could play an important role in applications such as document summarization ( Teufel and Moens , 2000 ) , information retrieval ( Tbahriti et al. , 2005 ) , information extraction ( Mizuta et al. , 2005 ) , and question answering .


This semantics was constructed ( Zadrozny 1987a , 1987b ) as a formal framework for default and commonsense reasoning .


There is a general consensus among theoretical linguists that the proper representation of verbal argument structure is event structure -- representations grounded in a theory of events that decompose semantic roles in terms of primitive predicates representing concepts such as causality and inchoativity ( Dowty , 1979 ; Jackendoff , 1983 ; Pustejovsky , 1991b ; Rappaport Hovav and Levin , 1998 ) .


Similarly , the notion of R + M-abduction is spiritually related to the `` abductive inference '' of Reggia ( 1985 ) , the `` diagnosis from first principles '' of Reiter ( 1987 ) , `` explainability '' of Poole ( 1988 ) , and the subset principle of Berwick ( 1986 ) .


The EDR has close ties to the named entity recognition ( NER ) and coreference resolution tasks , which have been the focus of several recent investigations ( Bikel et al. , 1997 ; Miller et al. , 1998 ; Borthwick , 1999 ; Mikheev et al. , 1999 ; Soon et al. , 2001 ; Ng and Cardie , 2002 ; Florian et al. , 2004 ) , and have been at the center of evaluations such as : MUC-6 , MUC-7 , and the CoNLL '02 and CoNLL '03 shared tasks .


Representative systems are described in Boisen et al. ( 1989 ) , De Mattia and Giachin ( 1989 ) , Niedermair ( 1989 ) , Niemann ( 1990 ) , and Young ( 1989 ) .


R98 ( , , , , â ) uses a variant of Kozima 's semantic similarity measure ( Kozima , 1993 ) to compute block similarity .


Liu et al. ( 2005 ) , Meral et al. ( 2007 ) , Murphy ( 2001 ) , Murphy and Vogel ( 2007 ) and Topkara et al. ( 2006a ) all belong to the syntactic transformation category .


We used a publicly available tagger ( Ratnaparkhi , 1996 ) to tag the words and then used these in the input to the system .


Some works abstract perception via the usage of symbolic logic representations ( Chen et al. , 2010 ; Chen and Mooney , 2011 ; Matuszek et al. , 2012 ; Artzi and Zettlemoyer , 2013 ) , while others choose to employ concepts elicited from psycholinguistic and cognition studies .


Multilingual lexical databases aligned with the English WordNet ( e.g. MultiWordNet ( Pianta et al. , 2002 ) ) have been created for several languages , with different degrees of coverage .


An off-the-shelf speech recognition device , a Nippon Electric Corporation DP-200 , was added to an existing natural language processing system , the Natural Language Computer ( NLC ) ( Ballard 1979 , Biermann and Ballard 1980 ) .


For future work , we might investigate how machine learning algorithms , which are specifically designed for the problem of domain adaptation ( Blitzer et al. , 2007 ; Jiang and Zhai , 2007 ) , perform in comparison to our approach .


But their importance has grown far beyond machine translation : for instance , transferring annotations between languages ( Yarowsky and Ngai 2001 ; Hwa et al. 2005 ; Ganchev , Gillenwater , and Taskar 2009 ) ; discovery of paraphrases ( Bannard and Callison-Burch 2005 ) ; and joint unsupervised POS and parser induction across languages ( Snyder and Barzilay 2008 ) .


That is , if the current hypothesis is unable to label a candidate or is uncertain about it , then the candidate might be a good training example ( Lewis and Catlett 1994 ) .


Other milestones of recent research include the deployment of probabilistic and machine learning techniques ( Aone and Bennett 1995 ; Kehler 1997 ; Ge , Hale , and Charniak 1998 ; Cardie and Wagstaff 1999 ; the continuing interest in centering , used either in original or in revised form ( Abracos and Lopes 1994 ; Strube and Hahn 1996 ; Hahn and Strube 1997 ; Tetreault 1999 ) ; and proposals related to the evaluation methodology in anaphora resolution ( Mitkov 1998a , 2001b ) .


For instance , the derived morphological forms are believed to be represented as a whole , whereas the representation of the inflected forms follows the morphemic model ( Caramazza et al. , 1988 ) .


We perceive that these results can be extended to other language models that properly embed bilexical context-free grammars , as for instance the more general history-based models used in ( Ratnaparkhi , 1997 ) and ( Chelba and Jelinek , 1998 ) .


Another paper ( Yoshinaga et al. , 2001 ) describes the detailed analysis on the factor of the difference of parsing performance .


The original and the obtained grammar generated exactly the same number of derivation trees in the parsing experiment with 457 sentences from the ATIS corpus ( Marcus et al. , 1994 ) 6 ( the average length is 6.32 words ) .


The use of running tallies and percentages is based on the assumption that these features are likely to produce generalized predictors ( Litman et al. , 1999 ) .


The Longman lexicographers have developed a grammar coding system capable of representing in compact form a nontrivial amount of information , usually to be found only in large descriptive grammars of English ( such as Quirk et al. , 1985 ) .


19 The paper by Alkuhlani and Habash ( 2012 ) presents additional , more sophisticated models that we do not use in this article .


Empirical evidence has been brought forward that inflectional and/or derivational stemmers augmented by dictionaries indeed perform substantially better than those without access to such lexical repositories ( Krovetz , 1993 ; Kraaij and Pohlmann , 1996 ; Tzoukermann et al. , 1997 ) .


Although there are other discussions of the paragraph as a central element of discourse ( e.g. Chafe 1979 , Halliday and Hasan 1976 , Longacre 1979 , Haberlandt et al. 1980 ) , all of them share a certain limitation in their formal techniques for analyzing paragraph structure .


( Details of how the average-expert model performs can be found in our prior work ( Xiong and Litman , 2011 ) . )


Self-training should also benefit other discriminatively trained parsers with latent annotations ( Petrov and Klein , 2008 ) , although training would be much slower compared to using generative models , as in our case .


We introduce here a clearly defined and replicable split of the ACE 2004 data , so that future investigations can accurately and correctly compare against the results presented here .


In most cases , the accuracy of parsers degrades when run on out-of-domain data ( Gildea , 2001 ; McClosky et al. , 2006 ; Blitzer et al. , 2006 ; Petrov et al. , 2010 ) .


Brent ( 1993 ) relies on morphosyntactic cues in the untagged Brown corpus as indicators of six predefined subcategorization frames .


To build the above s2t system , we first use the parse tree , which is generated by parsing the English side of the bilingual data with the Berkeley parser ( Petrov et al. , 2006 ) .


One obvious approach to this problem is to employ parser reranking ( Collins , 2000 ) .


Ideally , to distinguish between raising and equi verbs , a number of syntactic criteria should be employed ( Perlmutter and Soames , 1979:460 ff . )


The table also presents the closest comparable experimental results reported by McKnight and Srinivasan ( 2003 ) .1 McKnight and Srinivasan ( henceforth , M&S ) created a test collection consisting of 37,151 RCTs from approximately 12 million MEDLINE abstracts dated between 1976 and 2001 .


How this mismatched perceptual basis affects referential communication in situated dialogue was investigated in our previous work ( Liu et al. , 2012 ) .


Andrews et al. ( 2009 ) furthered this work by showing that a bimodal topic model , consisting of both text and feature norms , outperformed models using only one modality on the prediction of association norms , word substitution errors , and semantic interference tasks .


A cooccurrence based stemmer ( Xu and Croft , 1998 ) was used to stem Spanish words .


The best performance on the WSJ corpus was achieved by a combination of the SATZ system ( Palmer and Hearst 1997 ) with the Alembic system ( Aberdeen et al. 1995 ) : a 0.5 % error rate .


In a number of proposals , lexical generalizations are captured using lexical underspecification ( Kathol 1994 ; Krieger and Nerbonne 1992 ;


Although a grid may be more descriptively suitable for some aspects of prosody ( for example , Sproat and Liberman ( 1987 ) use the grid representation for their implementation of stress assignment in compound nominals ) , we are not aware of any evidence for or against a grid representation of discourseneutral phrasing .


The bottom panel of table 1 lists the results for the chosen lexicalized model ( SSN-Freq > 200 ) and five recent statistical parsers ( Ratnaparkhi , 1999 ; Collins , 1999 ; Charniak , 2000 ; Collins , 2000 ; Bod , 2001 ) .


Other factors , such as the role of focus ( Grosz 1977 , 1978 ; Sidner 1983 ) or quantifier scoping ( Webber 1983 ) must play a role , too .


linguistic in nature , rather than dealing with superficial properties of the text , e.g. the amount of white space between words ( Por et al. , 2008 ) .


The second version ( RM ) concerns the Resource Management task ( Pallett 1989 ) that has been popular within the DARPA community in recent years .


Another line of research that is correlated with ours is recognition of agreement/disagreement ( Misra and Walker , 2013 ; Yin et al. , 2012 ; Abbott et al. , 2011 ; Andreas et al. , 2012 ; Galley et al. , 2004 ; Hillard et al. , 2003 ) and classification of stances ( Walker et al. , 2012 ; Somasundaran and Wiebe , 2010 ) in online forums .


The studies presented by Goldwater and Griffiths ( 2007 ) and Johnson ( 2007 ) differed in the number of states that they used .


A number of alignment techniques have been proposed , varying from statistical methods ( Brown et al. , 1991 ; Gale and Church , 1991 ) to lexical methods ( Kay and Roscheisen , 1993 ; Chen , 1993 ) .


We would like to use features that look at wide context on the input side , which is inexpensive ( Jiampojamarn et al. , 2007 ) .


Much of the earlier work in anaphora resolution heavily exploited domain and linguistic knowledge ( Sidner 1979 ; Carter 1987 ; Rich and LuperFoy 1988 ; Carbonell and Brown 1988 ) , which was difficult both to represent and to process , and which required considerable human input .


Experiments on Chinese SRL ( Xue and Palmer 2005 , Xue 2008 ) reassured these findings .


This is then generalized , following a methodology based on Block ( 2000 ) , to generate the `` generalized marker lexicon . ''


A number of speech understanding systems have been developed during the past fifteen years ( Barnett et al. 1980 , Dixon and Martin 1979 , Erman et al. 1980 , Haton and Pierrel 1976 , Lea 1980 , Lowerre and Reddy 1980 , Medress 1980 , Reddy 1976 , Walker 1978 , and Wolf and Woods 1980 ) .


Our proposed method is based on the automatically acquired paraphrase dictionary described in Callison-Burch ( 2008 ) , in which the application of paraphrases from the dictionary encodes secret bits .


For example , frequent words are translated less consistently than rare words ( Melamed , 1997 ) .


Over the last decade there has been a lot of interest in developing tutorial dialogue systems that understand student explanations ( Jordan et al. , 2006 ; Graesser et al. , 1999 ; Aleven et al. , 2001 ; Buckley and Wolska , 2007 ; Nielsen et al. , 2008 ; VanLehn et al. , 2007 ) , because high percentages of selfexplanation and student contentful talk are known to be correlated with better learning in humanhuman tutoring ( Chi et al. , 1994 ; Litman et al. , 2009 ; Purandare and Litman , 2008 ; Steinhauser et al. , 2007 ) .


These knowledge sources were effectively used to build a state-of-the-art WSD program in one of our prior work ( Lee and Ng , 2002 ) .


Another line of research approaches grounded language knowledge by augmenting distributional approaches of word meaning with perceptual information ( Andrews et al. , 2009 ; Steyvers , 2010 ; Feng and Lapata , 2010b ; Bruni et al. , 2011 ; Silberer and Lapata , 2012 ; Johns and Jones , 2012 ; Bruni et al. , 2012a ; Bruni et al. , 2012b ; Silberer et al. , 2013 ) .


Due to advances in statistical syntactic parsing techniques ( Collins , 1997 ; Charniak , 2001 ) , attention has recently shifted towards the harder question of analyzing the meaning of natural language sentences .


This is where robust syntactic systems like SATZ ( Palmer and Hearst 1997 ) or the POS tagger reported in Mikheev ( 2000 ) , which do not heavily rely on word capitalization and are not sensitive to document length , have an advantage .


category relationships from the weak supervision : the tag dictionary and raw corpus ( Garrette and Baldridge , 2012 ; Garrette et al. , 2015 ) .4 This procedure attempts to automatically estimate the frequency of each word/tag combination by dividing the number of raw-corpus occurrences of each word in the dictionary evenly across all of its associated tags .


WIT has been implemented in Common Lisp and C on UNIX , and we have built several experimental and demonstration dialogue systems using it , including a meeting room reservation system ( Nakano et al. , 1999b ) , a video-recording programming system , a schedule management system ( Nakano et al. , 1999a ) , and a weather infomiation system ( Dohsaka et al. , 2000 ) .


Lexical functional grammar ( Kaplan and Bresnan 1982 ; Bresnan 2001 ; Dalrymple 2001 ) is a member of the family of constraint-based grammars .


Sarkar and Zeman ( 2000 ) present an approach to learn previously unknown frames for Czech from the Prague Dependency Bank ( Hajic


A companion paper describes the evaluation process and results in further detail ( Chu-Carroll and Nickerson , 2000 ) .


SNoW ( Carleson et al. , 1999 ; Roth , 1998 ) is a multi-class classifier that is specifically tailored for learning in domains in which the potential number of information sources ( features ) taking part in decisions is very large , of which NLP is a principal example .


Hence , enumerating morphological variants in a semi-automatically generated lexicon , such as proposed for French ( Zweigenbaum et al. , 2001 ) , turns out to be infeasible , at least for German and related languages .


It is analogous to the step in other translation model induction algorithms that sets all probabilities below a certain threshold to negligible values ( Brown et al. , 1990 ; Dagan et al. , 1993 ; Chen , 1996 ) .


They proved to be useful in a number of NLP applications such as natural language generation ( Iordanskaja et al. , 1991 ) , multidocument summarization ( McKeown et al. , 2002 ) , automatic evaluation of MT ( Denkowski and Lavie , 2010 ) , and TE ( Dinu and Wang , 2009 ) .


The results , which partly confirm those obtained on a smaller dataset in Paggio and Navarretta ( 2010 ) , must be seen in light of the fact that our gesture annotation scheme comprises more fine-grained categories than most of the studies mentioned earlier for both head movements and face expressions .


We employ the idea of ultraconservative update ( Crammer and Singer , 2003 ; Crammer et al. , 2006 ) to propose two incremental methods for local training in Algorithm 2 as follows .


It has also been shown to be useful in joint inference of text with visual attributes obtained using visual classifiers ( Silberer et al. , 2013 ) .


Gurevych ( 2006 ) reported a correlation of r = .69 .


A more subtle example is weighted FSAs that approximate PCFGs ( Nederhof , 2000 ; Mohri and Nederhof , 2001 ) , or to extend the idea , weighted FSTs that approximate joint or conditional synchronous PCFGs built for translation .


As has been previously observed and exploited in the NLP literature ( Pang and Lee , 2004 ; Agarwal and Bhattacharyya , 2005 ; Barzilay and Lapata , 2005 ) , the above optimization function , unlike many others that have been proposed for graph or set partitioning , can be solved exactly in an provably efficient manner via methods for finding minimum cuts in graphs .


WIT features an incremental understanding method ( Nakano et al. , 1999b ) that makes it possible to build a robust and real-time system .


This choice is inspired by recent work on learning syntactic categories ( Yatbaz et al. , 2012 ) , which successfully utilized such language models to represent word window contexts of target words .


As for work on Arabic ( MSA ) , results have been reported on the PATB ( Kulick , Gabbard , and Marcus 2006 ; Diab 2007 ; Green and Manning 2010 ) , the Prague Dependency Treebank ( PADT ) ( Buchholz and Marsi 2006 ; Nivre 2008 ) and the CATiB ( Habash and Roth 2009 ) .


Other studies which view lR as a query generation process include Maron and Kuhns , 1960 ; Hiemstra and Kraaij , 1999 ; Ponte and Croft , 1998 ; Miller et al , 1999 .


In Section 5 , we discuss the difficulties associated with such user studies , and describe a human-based evaluation we conducted for a small subset of the responses generated by our system ( Marom and Zukerman 2007b ) .


Hook ( 1981 ) considers the second verb V2 as an aspectual complex comparable to the auxiliaries .


2We could just as easily use other symmetric `` association '' measures , such as 02 ( Gale & Church , 1991 ) or the Dice coefficient ( Smadja , 1992 ) .


In this situation , Brown et al. ( 1993b , 293 ) recommend `` evaluating the expectations using only a single , probable alignment . ''


The use of the web as a corpus for teaching and research on language has been proposed a number of times ( Kilgarriff , 2001 ; Robb , 2003 ; Rundell , 2000 ; Fletcher , 2001 , 2004b ) and received a special issue of the journal Computational Linguistics ( Kilgarriff and Grefenstette , 2003 ) .


â¢ Learnability ( Zernik and Dyer 1987 ) â¢ Text generation ( Hovy 1988 ; Milosavljevic , Tulloch , and Dale 1996 ) â¢ Speech generation ( Rayner and Carter 1997 ) â¢ Localization ( Sch Â¨ aler 1996 )


Following our previous work on stance classification ( Hasan and Ng , 2013c ) , we employ three types of features computed based on the frame-semantic parse of each sentence in a post obtained from SEMAFOR ( Das et al. , 2010 ) .


However , the literature on Linguistic Steganography , in which linguistic properties of a text are modified to hide information , is small compared with other media ( Bergmair , 2007 ) .


This has been reported for other languages , too , dependent on the generality of the chosen approach ( J Â¨ appinen and Niemist Â¨ o , 1988 ; Choueka , 1990 ; Popovic and Willett , 1992 ; Ekmekc Â¸ ioglu et al. , 1995 ; Hedlund et al. , 2001 ; Pirkola , 2001 ) .


We offer a theorem that highlights the broad applicability of these modeling techniques .4 If f ( input , output ) is a weighted regular relation , then the following statements are equivalent : ( 1 ) f is a joint probabilistic relation ; ( 2 ) f can be computed by a Markovian FST that halts with probability 1 ; ( 3 ) f can be expressed as a probabilistic regexp , i.e. , a regexp built up from atomic expressions a : b ( for a E E U -LCB- E -RCB- , b E A U -LCB- E -RCB- ) using concatenation , probabilistic union + p , and probabilistic closure * p. For defining conditional relations , a good regexp language is unknown to us , but they can be defined in several other ways : ( 1 ) via FSTs as in Fig. 1c , ( 2 ) by compilation of weighted rewrite rules ( Mohri and Sproat , 1996 ) , ( 3 ) by compilation of decision trees ( Sproat and Riley , 1996 ) , ( 4 ) as a relation that performs contextual left-to-right replacement of input substrings by a smaller conditional relation ( Gerdemann and van Noord , 1999 ) ,5 ( 5 ) by conditionalization of a joint relation as discussed below .


We use the Clark and Curran ( 2007 ) CCG parser to analyse the sentence before and after paraphrasing .


For example , consider a relational description ( cfXXX , Dale and Haddock 1991 ) involving a gradable adjective , as in the dog in the large shed .


Previous versions of our work , as described in Bachenko et al. ( 1986 ) also assume that phrasing is dependent on predicate-argument structure .


like information extraction ( Yates and Etzioni , 2009 ) and textual entailment ( Berant et al. , 2010 ) .


The inclusion of the coreference task in the Sixth and Seventh Message Understanding Conferences ( MUC-6 and MUC-7 ) gave a considerable impetus to the development of coreference resolution algorithms and systems , such as those described in Baldwin et al. ( 1995 ) , Gaizauskas and Humphreys ( 1996 ) , and Kameyama ( 1997 ) .


Lee et al. ( 2012 ) model entity coreference and event coreference jointly ; Durrett and Klein ( 2014 ) consider joint coreference and entity-linking .


However , learning-based resolvers have not been able to benefit from having an SC agreement feature , presumably because the method used to compute the SC of an NP is too simplistic : while the SC of a proper name is computed fairly accurately using a named entity ( NE ) recognizer , many resolvers simply assign to a common noun the first ( i.e. , most frequent ) WordNet sense as its SC ( e.g. , Soon et al. ( 2001 ) , Markert and Nissim ( 2005 ) ) .


This includes work on generalized expectation ( Mann and McCallum , 2010 ) , posterior regularization ( Ganchev et al. , 2010 ) and constraint driven learning ( Chang et al. , 2007 ; Chang et al. , 2010 ) .


The final machine is a trigram language model , specifically a Kneser-Ney ( Chen and Goodman , 1998 ) based backoff language model .


Hovy has described another text planner that builds similar plans ( Hovy 1988b ) .


In particular , since we treat each individual speech within a debate as a single `` document '' , we are considering a version of document-level sentiment-polarity classification , namely , automatically distinguishing between positive and negative documents ( Das and Chen , 2001 ; Pang et al. , 2002 ; Turney , 2002 ; Dave et al. , 2003 ) .


transition-based dependency parsing framework ( Nivre , 2008 ) using an arc-eager transition strategy and are trained using the perceptron algorithm as in Zhang and Clark ( 2008 ) with a beam size of 8 .


Just as easily , we can model link types that coincide with entries in an on-line bilingual dictionary separately from those that do not ( cfXXX Brown et al. 1993 ) .


As an alternative , we rely on PubMed to retrieve an initial set of hits that we then postprocess in greater detail -- this is the standard pipeline architecture commonly employed in other question-answering systems ( Voorhees and Tice 1999 ; Hirschman and Gaizauskas 2001 ) .


( Och and Ney , 2002 ; Blunsom et al. , 2008 ) used maximum likelihood estimation to learn weights for MT. ( Och , 2003 ; Moore and Quirk , 2008 ; Zhao and Chen , 2009 ; Galley and Quirk , 2011 ) employed an evaluation metric as a loss function and directly optimized it .


We also compare the results with the output generated by the statistical translation system GIZA + + / ISI ReWrite Decoder ( AlOnaizan et al. , 1999 ; Och and Ney , 2000 ; Germann et al. , 2001 ) , trained on the same parallel corpus .


Some efforts have tackled tasks such as automatic image caption generation ( Feng and Lapata , 2010a ; Ordonez et al. , 2011 ) , text illustration ( Joshi et al. , 2006 ) , or automatic location identification of Twitter users ( Eisenstein et al. , 2010 ; Wing and Baldridge , 2011 ; Roller et al. , 2012 ) .


Since we are not generating from the model , this does not introduce difficulties ( Klein and Manning , 2002 ) .


The extraction procedure consists of three steps : First , the bracketing of the trees in the Penn Treebank is corrected and extended based on the approaches of Magerman ( 1994 ) and Collins ( 1997 ) .


As they are required to enable test subjects to distinguish between senses , we use artificial glosses composed from synonyms and hypernyms as a surrogate , e.g. for brother : `` brother , male sibling '' vs. `` brother , comrade , friend '' ( Gurevych , 2005 ) .


Over the last decade there has been a lot of interest in developing tutorial dialogue systems that understand student explanations ( Jordan et al. , 2006 ; Graesser et al. , 1999 ; Aleven et al. , 2001 ; Buckley and Wolska , 2007 ; Nielsen et al. , 2008 ; VanLehn et al. , 2007 ) , because high percentages of selfexplanation and student contentful talk are known to be correlated with better learning in humanhuman tutoring ( Chi et al. , 1994 ; Litman et al. , 2009 ; Purandare and Litman , 2008 ; Steinhauser et al. , 2007 ) .


Dalrymple ( 2001 ) argues that there are cases , albeit exceptional ones , in which constraints on syntactic category are an issue in subcategorization .


Corpus frequency : ( Vosse , 1992 ) differentiates between misspellings and neologisms ( new words ) in terms of their frequency .


We use an in-house developed hierarchical phrase-based translation ( Chiang , 2005 ) as our baseline system , and we denote it as In-Hiero .


The types of sentences accepted are essentially those accepted by the original NLC grammar , imperative sentences with nested noun groups and conjunctions ( Ballard 1979 ) .


The task we used to compare different generalisation techniques is similar to that used by Pereira et al. ( 1993 ) and Rooth et al. ( 1999 ) .


One of the proposed methods to extract paraphrases relies on a pivot-based approach using phrase alignments in a bilingual parallel corpus ( Bannard and Callison-Burch , 2005 ) .


The Nash arbitration plan , for example , would allow a doubly graded description whenever the product of the Values for the referent r exceeds that of all distractors ( Nash 1950 ; cfXXX Gorniak and Roy 2003 ; Thorisson 1994 , for other plans ) .


Turney ( 2001 ) extracts word co-occurrence probabilities from unlabelled text collected from a web crawler .


Notable early papers on graph-based semisupervised learning include Blum and Chawla ( 2001 ) , Bansal et al. ( 2002 ) , Kondor and Lafferty ( 2002 ) , and Joachims ( 2003 ) .


Due to this inherent ambiguity , manual annotations usually distinguish between sure correspondences for unambiguous translations , and possible , for ambiguous translations ( Och and Ney 2003 ) .


Thus for instance , ( Copestake and Flickinger , 2000 ; Copestake et al. , 2001 ) describes a Head Driven Phrase Structure Grammar ( HPSG ) which supports the parallel construction of a phrase structure ( or derived ) tree and of a semantic representation and ( Dalrymple , 1999 ) show how to equip Lexical Functional grammar ( LFG ) with a glue semantics .


The contextual interpreter then uses a reference resolution approach similar to Byron ( 2002 ) , and an ontology mapping mechanism ( Dzikovska et al. , 2008a ) to produce a domain-specific semantic representation of the student 's output .


only the available five relative scopings of the quantifiers are produced ( Hobbs and Shieber 1987 , 47 ) , but without the need for a free variable constraint -- the HOU algorithm will not produce any solutions in which a previously bound variable becomes free ; â¢ the equivalences are reversible , and thus the above sentences cart be generated from scoped logical forms ; â¢ partial scopings are permitted ( see Reyle [ 19961 ) â¢ scoping can be freely interleaved with other types of reference resolution ; â¢ unscoped or partially scoped forms are available for inference or for generation at every stage .


In the transducers produced by the training method described in this paper , the source and target positions are in the set -LCB- -1 , 0,1 -RCB- , though we have also used handcoded transducers ( Alshawi and Xia 1997 ) and automatically trained transducers ( Alshawi and Douglas 2000 ) with a larger range of positions .


Similar approaches are being explored for parsing ( Steedman , Hwa , et al. 2003 ; Hwa et al. 2003 ) .


In particular , since we treat each individual speech within a debate as a single `` document '' , we are considering a version of document-level sentiment-polarity classification , namely , automatically distinguishing between positive and negative documents ( Das and Chen , 2001 ; Pang et al. , 2002 ; Turney , 2002 ; Dave et al. , 2003 ) .


would be chunked as follows ( Tjong Kim Sang and Buchholz , 2000 ) : [ NP He ] [ VP reckons ] [ NP the current account deficit ] [ VP will narrow ] [ PP


The flexible architecture we have presented enables interesting future research : ( i ) a straightforward improvement is the use of lexical similarity to reduce data sparseness , e.g. ( Basili et al. , 2005 ; Basili et al. , 2006 ; Bloehdorn et al. , 2006 ) .


5An alternative strategy to step ( 4 ) is to perform a database lookup based on the ambiguous query and summarize the results ( Litman et al. , 1998 ) , which we leave for future work .


Such approaches have been tried recently in restricted cases ( McCallum et al. , 2000 ; Eisner , 2001b ; Lafferty et al. , 2001 ) .


Typed feature grammars can be used as the basis for implementations of Head-driven Phrase Structure Grammar ( HPSG ; Pollard and Sag , 1994 ) as discussed in ( Gotz and Meurers , 1997a ) and ( Meurers and Minnen , 1997 ) .


It is therefore no surprise that early attempts at response automation were knowledge-driven ( Barr and Tessler 1995 ; Watson 1997 ; Delic and Lahaix 1998 ) .


A more subtle example is weighted FSAs that approximate PCFGs ( Nederhof , 2000 ; Mohri and Nederhof , 2001 ) , or to extend the idea , weighted FSTs that approximate joint or conditional synchronous PCFGs built for translation .


ones , DIRT ( Lin and Pantel , 2001 ) , VerbOcean ( Chklovski and Pantel , 2004 ) , FrameNet ( Baker et al. , 1998 ) , and Wikipedia ( Mehdad et al. , 2010 ; Kouylekov et al. , 2009 ) .


The Ruby on Rails ( 2006 ) framework permits us to quickly develop web applications without rewriting common functions and classes .


We further add rules for combining with punctuation to the left and right and allow for the merge rule X â X X of Clark and Curran ( 2007 ) .


Politically-oriented text Sentiment analysis has specifically been proposed as a key enabling technology in eRulemaking , allowing the automatic analysis of the opinions that people submit ( Shulman et al. , 2005 ; Cardie et al. , 2006 ; Kwon et al. , 2006 ) .


Moschitti et al. ( 2005 ) has made some preliminary attempt on the idea of hierarchical semantic


Morris and Hirst ( 2004 ) pointed out that many relations between words in a text are non-classical ( i.e. other than typical taxonomic relations like synonymy or hypernymy ) and therefore not covered by semantic similarity .


Some of the intuitions we associate with this notion have been very well expressed by Turner ( 1987 , pp. 7-8 ) : ... Semantics is constrained by our models of ourselves and our worlds .


In 2009 , the second WePS campaign showed similar trends regarding the use of NE features ( Artiles et al. , 2009 ) .


The head words can be automatically extracted using a heuristic table lookup in the manner described by Magerman ( 1994 ) .


Reiter describes a pipelined modular approach as a consensus architecture underlying most recent work in generation ( Reiter 1994 ) .


For example , the suite of LT tools ( Mikheev et al. , 1999 ; Grover et al. , 2000 ) perform tokenization , tagging and chunking on XML marked-up text directly .


Liu et al. ( 2005 ) , Meral et al. ( 2007 ) , Murphy ( 2001 ) , Murphy and Vogel ( 2007 ) and Topkara et al. ( 2006a ) all belong to the syntactic transformation category .


Brockmann and Lapata ( 2003 ) have showed that WordNet-based approaches do not always outperform simple frequency-based models , and a number of techniques have been recently proposed which may offer ideas for refining our current unsupervised approach ( Erk , 2007 ; Bergsma et al. , 2008 ) .


The RenTAL system is implemented in LiLFeS ( Makino et al. , 1998 ) 2 .


In the future , we hope to evaluate the automatic annotations and extracted lexicon against Propbank ( Kingsbury and Palmer 2002 ) .


Each set of translations is stored separately , and for each set the `` marker hypothesis '' ( Green 1979 ) is used to segment the phrasal lexicon into a `` marker lexicon . ''


One way to increase the precision of the mapping process is to impose some linguistic constraints on the sequences such as simple noun-phrase contraints ( Gaussier , 1995 ; Kupiec , 1993 ; hua Chen and Chen , 94 ; Fung , 1995 ; Evans and Zhai , 1996 ) .


Although this study falls under the general topic of discourse modeling , our work differs from previous attempts to characterize text in terms of domainindependent rhetorical elements ( McKeown , 1985 ; Marcu and Echihabi , 2002 ) .


`` Coherence , '' as outlined above , can be understood as a declarative ( or static ) version of marker passing ( Hirst 1987 ; Charniak 1983 ) , with one difference : the activation spreads to theories that share a predicate , not through the IS-A hierarchy , and is limited to elementary facts about predicates appearing in the text .


Task properties Determining whether or not a speaker supports a proposal falls within the realm of sentiment analysis , an extremely active research area devoted to the computational treatment of subjective or opinion-oriented language ( early work includes Wiebe and Rapaport ( 1988 ) , Hearst ( 1992 ) , Sack ( 1994 ) , and Wiebe ( 1994 ) ; see Esuli ( 2006 ) for an active bibliography ) .


First , it has been noted that in many natural language applications it is sufficient to use shallow parsing information ; information such as noun phrases ( NPs ) and other syntactic sequences have been found useful in many large-scale language processing applications including information extraction and text summarization ( Grishman , 1995 ; Appelt et al. , 1993 ) .


In addition , a fully flexible access system allows the retrieval of dictionary entries on the basis of constraints specifying any combination of phonetic , lexical , syntactic , and semantic information ( Boguraev et al. , 1987 ) .


Clarkson and Robinson ( 1997 ) developed a way of incorporating standard n-grams into the cache model , using mixtures of language models and also exponentially decaying the weight for the cache prediction depending on the recency of the word 's last


Riehemann 1993 ; Oliva 1994 ; Frank 1994 ; Opalka 1995 ; Sanfilippo 1995 ) .


Machine learning methods should be interchangeable : Transformation-based learning ( TBL ) ( Brill , 1993 ) and Memory-based learning ( MBL ) ( Daelemans et al. , 2002 ) have been applied to many different problems , so a single interchangeable component should be used to represent each method .


Recently , several alternative , often quite sophisticated approaches to collective classification have been proposed ( Neville and Jensen , 2000 ; Lafferty et al. , 2001 ; Getoor et al. , 2002 ; Taskar et al. , 2002 ; Taskar et al. , 2003 ; Taskar et al. , 2004 ; McCallum and Wellner , 2004 ) .


We tested the classification of verbs into semantic types using a verb list of 139 pre-classified items drawn from the lists published in Rosenbaum ( 1967 ) and Stockwell et al. ( 1973 ) .


The combination of likelihood and prior modeling , HMMs , and Viterbi decoding is fundamentally the same as the standard probabilistic approaches to speech recognition ( Bahl , Jelinek , and Mercer 1983 ) and tagging ( Church 1988 ) .


Cross-lingual Textual Entailment ( CLTE ) has been proposed by ( Mehdad et al. , 2010 ) as an extension of Textual Entailment ( Dagan and Glickman , 2004 ) that consists in deciding , given two texts T and H in different languages , if the meaning of H can be inferred from the meaning of T .


The EDR has close ties to the named entity recognition ( NER ) and coreference resolution tasks , which have been the focus of several recent investigations ( Bikel et al. , 1997 ; Miller et al. , 1998 ; Borthwick , 1999 ; Mikheev et al. , 1999 ; Soon et al. , 2001 ; Ng and Cardie , 2002 ; Florian et al. , 2004 ) , and have been at the center of evaluations such as : MUC-6 , MUC-7 , and the CoNLL '02 and CoNLL '03 shared tasks .


Other solutions such as complete caching of the corpora are not typically adopted due to legal concerns over copyright and redistribution of web data , issues considered at length by Fletcher ( 2004a ) .


This includes work on generalized expectation ( Mann and McCallum , 2010 ) , posterior regularization ( Ganchev et al. , 2010 ) and constraint driven learning ( Chang et al. , 2007 ; Chang et al. , 2010 ) .


A very similar formulation , for another grammar transformation , is given in Nederhof ( 1998 ) .


We run GIZA + + ( Och and Ney , 2000 ) on the training corpus in both directions ( Koehn et al. , 2003 ) to obtain the word alignment for each sentence pair .


Other attempts to address efficiency include the fast Transformation Based Learning ( TBL ) Toolkit ( Ngai and Florian , 2001 ) which dramatically speeds up training TBL systems , and the translation of TBL rules into finite state machines for very fast tagging ( Roche and Schabes , 1997 ) .


Consequently , fusion has been applied to a wide variety of pattern recognition and decision theoretic problems -- using a plethora of theories , techniques , and tools -- including some applications in computational linguistics ( e.g. , Brill and Wu 1998 ; van Halteren , Zavrel , and Daelemans 1998 ) and speech technology ( e.g. , Bowles and Damper 1989 ; Romary and Pierre11989 ) .


This observation has led some researchers , e.g. , Cooper and Paccia-Cooper ( 1980 ) , to claim a direct mapping between the syntactic phrase and the prosodic phrase .


These features are carefully designed to reduce the data sparseness problem and some of them are inspired by previous work ( He et al. , 2008 ; Gimpel and Smith , 2008 ; Marton and Resnik , 2008 ; Chiang et al. , 2009 ; Setiawan et al. , 2009 ; Shen et al. , 2009 ; Xiong et al. , 2009 ) : 1 .


In our previous work ( Zhang and Chai , 2009 ) , conversation entailment is formulated as the following : given a conversation segment D which is represented by a set of clauses D = d1 â§ ... â§ dm , and a hypothesis H represented by another set of clauses H = h1 â§ ... â§ hn , the prediction on whether D entails H is determined by the product of probabilities that each hypothesis clause hj is entailed from all the conversation segment clauses d1 ... dm as follows .


Notable early papers on graph-based semisupervised learning include Blum and Chawla ( 2001 ) , Bansal et al. ( 2002 ) , Kondor and Lafferty ( 2002 ) , and Joachims ( 2003 ) .


In addition , we consider several types of lexical features ( LexF ) inspired by previous work on agreement and disagreement ( Galley et al. , 2004 ; Misra and Walker , 2013 ) .


Berger et al. ( 2000 ) compared two retrieval approaches ( TF.IDF and query expansion ) and two predictive approaches ( statistical translation and latent variable models ) .


Others provide automatic mappings of natural language instructions to executable actions , such as interpreting navigation directions ( Chen and Mooney , 2011 ) or robot commands ( Tellex et al. , 2011 ; Matuszek et al. , 2012 ) .


The dialogue state is represented by a cumulative answer analysis which tracks , over multiple turns , the correct , incorrect , and not-yet-mentioned parts 1Other factors such as student confidence could be considered as well ( Callaway et al. , 2007 ) .


As noted above , it is well documented ( Roland and Jurafsky 1998 ) that subcategorization frames ( and their frequencies ) vary across domains .


Chen and Vijay-Shanker ( 2000 ) explore a number of related approaches to the extraction of a lexicalized TAG from the Penn-II Treebank with the aim of constructing a statistical model for parsing .


At the same time , we believe our method has advantages over the approach developed initially at IBM ( Brown et al. 1990 ; Brown et al. 1993 ) for training translation systems automatically .


Building on the work of Ruch et al. ( 2003 ) in the same domain , we present a generative approach that attempts to directly model the discourse structure of MEDLINE abstracts using Hidden Markov Models ( HMMs ) ; cfXXX ( Barzilay and Lee , 2004 ) .


The basic Python reflection has already been implemented and used for large scale experiments with POS tagging , using pyMPI ( a message passing interface library for Python ) to coordinate experiments across a cluster of over 100 machines ( Curran and Clark , 2003 ; Clark et al. , 2003 ) .


As an alternative , we rely on PubMed to retrieve an initial set of hits that we then postprocess in greater detail -- this is the standard pipeline architecture commonly employed in other question-answering systems ( Voorhees and Tice 1999 ; Hirschman and Gaizauskas 2001 ) .


The language grounding problem has received significant attention in recent years , owed in part to the wide availability of data sets ( e.g. Flickr , Von Ahn ( 2006 ) ) , computing power , improved computer vision models ( Oliva and Torralba , 2001 ; Lowe , 2004 ; Farhadi et al. , 2009 ; Parikh and Grauman , 2011 ) and neurological evidence of ties between the language , perceptual and motor systems in the brain ( Pulverm Â¨ uller et al. , 2005 ; Tettamanti et al. , 2005 ; Aziz-Zadeh et al. , 2006 ) .


Although in this paper we take modus ponens as the main rule of inference , in general one can consider deductive closures with respect to weaker , nonstandard logics , ( cfXXX Levesque 1984 ; Frisch 1987 ; Patel-Schneider 1985 ) .


As Alshawi ( 1987 ) points out , given that no situations were envisaged where the information from the tape would be altered once installed in secondary storage , this simple and convenComputational Linguistics , Volume 13 , Numbers 3-4 , July-December 1987 205 Bran Boguraev and Ted Briscoe Large Lexicons for Natural Language Processing tional access strategy is perfectly adequate .


Other factors , such as the role of focus ( Grosz 1977 , 1978 ; Sidner 1983 ) or quantifier scoping ( Webber 1983 ) must play a role , too .


This paper describes an approach for sharing resources in various grammar formalisms such as Feature-Based Lexicalized Tree Adjoining Grammar ( FB-LTAG1 ) ( Vijay-Shanker , 1987 ; Vijay-Shanker and Joshi , 1988 ) and Head-Driven Phrase Structure Grammar ( HPSG ) ( Pollard and Sag , 1994 ) by a method of grammar conversion .


This is because the binary structure has been verified to be very effective for tree-based translation ( Wang et al. , 2007 ; Zhang et al. , 2011a ) .


There is a general consensus among theoretical linguists that the proper representation of verbal argument structure is event structure -- representations grounded in a theory of events that decompose semantic roles in terms of primitive predicates representing concepts such as causality and inchoativity ( Dowty , 1979 ; Jackendoff , 1983 ; Pustejovsky , 1991b ; Rappaport Hovav and Levin , 1998 ) .


measure the standard intrinsic parser metrics unlabeled attachment score ( UAS ) and labeled attachment score ( LAS ) ( Buchholz and Marsi , 2006 ) .


The EDR has close ties to the named entity recognition ( NER ) and coreference resolution tasks , which have been the focus of several recent investigations ( Bikel et al. , 1997 ; Miller et al. , 1998 ; Borthwick , 1999 ; Mikheev et al. , 1999 ; Soon et al. , 2001 ; Ng and Cardie , 2002 ; Florian et al. , 2004 ) , and have been at the center of evaluations such as : MUC-6 , MUC-7 , and the CoNLL '02 and CoNLL '03 shared tasks .


Accordingly , we convert examples such as ( 27 ) into their generalized equivalents , as in ( 28 ) : ( 28 ) <DET> good man : bon homme That is , where Block ( 2000 ) substitutes variables for various words in his templates , we replace certain lexical items with their marker tag .


How it is done is beyond the scope of this paper but is explained in detail in Fink ( 1983 ) .


These tools use a highly optimised GIS implementation and provide sophisticated Gaussian smoothing ( Chen and Rosenfeld , 1999 ) .


Also relevant is work on the general problems of dialog-act tagging ( Stolcke et al. , 2000 ) , citation analysis ( Lehnert et al. , 1990 ) , and computational rhetorical analysis ( Marcu , 2000 ; Teufel and Moens , 2002 ) .


The inference rules that were necessary to convert one list of properties into another do not sit comfortably within the received NLG pipeline model ( e.g. , Reiter and Dale 2000 ) .


Niyogi ( 2001 ) has developed an agenda-driven chart parser for the feature-driven formalism described above ; please refer to his paper for a description of the parsing algorithm .


An example of psycholinguistically oriented research work can be found in Bond and Hayes ( 1983 ) .


In addition to a referring function , noun phrases ( NP ) can also serve communicative goals such as providing new information about the referent and expressing the speaker 's emotional attitude towards the referent ( Appelt , 1985 ; Jordan , 2000 ) .


Some well-known approaches include rule-based models ( Brill and Resnik 1994 ) , backed-off models ( Collins and Brooks 1995 ) , and a maximumentropy model ( Ratnaparkhi 1998 ) .


There is some literature on procedure acquisition such as the LISP synthesis work described in Biermann et al. ( 1984 ) and the PROLOG synthesis method of Shapiro ( 1982 ) .


Against the background of a growing interest in multilingual NLP , multilingual anaphora / coreference resolution has gained considerable momentum in recent years ( Aone and McKee 1993 ; Azzam , Humphreys , and Gaizauskas 1998 ; Harabagiu and Maiorano 2000 ; Mitkov and Barbu 2000 ; Mitkov 1999 ; Mitkov and Stys 1997 ; Mitkov , Belguith , and Stys 1998 ) .


The list of semantic relations with which we work is based on extensive literature study ( Barker et al. , 1997a ) .


The research described below is taking place in the context of three collaborative projects ( Boguraev , 1987 ; Russell et al. , 1986 ; Phillips and Thompson , 1986 ) to develop a general-purpose , wide coverage morphological and syntactic analyser for English .


In most cases , the accuracy of parsers degrades when run on out-of-domain data ( Gildea , 2001 ; McClosky et al. , 2006 ; Blitzer et al. , 2006 ; Petrov et al. , 2010 ) .


This paper presents experiments with generative content models for analyzing the discourse structure of medical abstracts , which has been confirmed to follow the four-section pattern discussed above ( Salanger-Meyer , 1990 ) .


Following Lekakos and Giaglis ( 2007 ) , one approach for achieving this objective consists of applying supervised learning , where a winning method is selected for each case in the training set , all the training cases are labeled accordingly , and then the system is trained to predict a winner for unseen cases .


Thus , over the past few years , along with advances in the use of learning and statistical methods for acquisition of full parsers ( Collins , 1997 ; Charniak , 1997a ; Charniak , 1997b ; Ratnaparkhi , 1997 ) , significant progress has been made on the use of statistical learning methods to recognize shallow parsing patterns syntactic phrases or words that participate in a syntactic relationship ( Church , 1988 ; Ramshaw and Marcus , 1995 ; Argamon et al. , 1998 ; Cardie and Pierce , 1998 ; Munoz et al. , 1999 ; Punyakanok and Roth , 2001 ; Buchholz et al. , 1999 ; Tjong Kim Sang and Buchholz , 2000 ) .


Due to their remarkable ability to incorporate context structure information and long distance reordering into the translation process , tree-based translation models have shown promising progress in improving translation quality ( Liu et al. , 2006 , 2009 ; Quirk et al. , 2005 ; Galley et al. , 2004 , 2006 ; Marcu et al. , 2006 ; Shen et al. , 2008 ; Zhang et al. , 2011b ) .


11 Nivre ( 2008 ) reports that non-projective and pseudo-projective algorithms outperform the `` eager '' projective algorithm in MaltParser , but our training data did not contain any non-projective dependencies .


In particular , boosting ( Schapire , 1999 ; Abney et al. , 1999 ) offers the possibility of achieving high accuracy from a collection of classifiers which individually perform quite poorly .


For MT the most commonly used heuristic is called grow diagonal final ( Och and Ney 2003 ) .


ECM-F is an entity-constrained mention Fmeasure ( cfXXX ( Luo et al. , 2004 ) for how ECM-F is computed ) , and ACE-Value is the official ACE evaluation metric .


In order to obtain semantic representations of each word , we apply our previous strategy ( Schone and Jurafsky ( 2000 ) ) .


Finkelstein et al. ( 2002 ) annotated a larger set of word pairs ( 353 ) , too .


A more flexible approach is used by Reiter and Sripada ( 2002 ) , where users can specify boundary values for attributes like rainfall , specifying , for example , rain counts as moderate above 7 mm/h , as heavy above 20 mm/h , and so on .


Furthermore , a number of performance features , largely based on the PARADISE dialogue evaluation scheme ( Walker et al. , 1997 ) , were automatically logged , derived , or manually annotated .


Shaw and Hatzivassiloglou ( 1999 ) propose to generalize the direct evidence method so that it can apply to unseen pairs of adjectives by computing the transitive closure of the ordering relation .


We evaluated our translations with IBM 's BLEU evaluation metric ( Papineni et al. , 2001 ) , using the same evaluation method and reference retranslations that were used for evaluation at HLT Workshop 2002 at CLSP ( Haji 6 et al. , 2002 ) .


Other attempts to address efficiency include the fast Transformation Based Learning ( TBL ) Toolkit ( Ngai and Florian , 2001 ) which dramatically speeds up training TBL systems , and the translation of TBL rules into finite state machines for very fast tagging ( Roche and Schabes , 1997 ) .


PR is closely related to the work of Mann and McCallum ( 2007 , 2008 ) , who concurrently developed the idea of using penalties based on posterior expectations of features to guide semi-supervised learning .


The best results on most of our data were obtained using Hidden Naive Bayes ( HNB ) ( Zhang et al. , 2005 ) .


de URL : http://www.sfs.nphil.uni-tuebingen.de/sfb / b4home.html 1 This is , for example , the case for all proposals working with verbal lexical entries that raise the arguments of a verbal complement ( Hinrichs and Nakazawa 1989 ) that also use lexical rules such as the Complement Extraction Lexical Rule ( Pollard and Sag 1994 ) or the Complement Cliticization Lexical Rule ( Miller and Sag 1993 ) to operate on those raised elements .


A number of proposals in the 1990s deliberately limited the extent to which they relied on domain and/or linguistic knowledge and reported promising results in knowledge-poor operational environments ( Dagan and Itai 1990 , 1991 ; Lappin and Leass 1994 ; Nasukawa 1994 ; Kennedy and Boguraev 1996 ; Williams , Harvey , and Preston 1996 ; Baldwin 1997 ; Mitkov 1996 , 1998b ) .


ASARES has been previously applied to the acquisition of word pairs sharing semantic relations defined in the Generative Lexicon framework ( Pustejovsky , 1995 ) and called qualia relations ( Bouillon et al. , 2001 ) .


mlSystem ruleFeats + atomFeats We augment mlSystem ruleFeats with more features from our previous work ( Markert et al. , 2012 ; Hou et al. , 2013a ; Hou et al. , 2013b ) on bridging anaphora recognition and antecedent selection .


The description of the EAGLE workbench for linguistic engineering ( Baldwin et al. 1997 ) mentions a case normalization module that uses a heuristic in which a capitalized word in an ambiguous position should be rewritten without capitalization if it is found lower-cased in the same document .


An exception is Grefenstette et al. ( 2004 ) , who experimented with determining the political orientation of websites essentially by classifying the concatenation of all the documents found on that site .


Until now , translation models have been evaluated either subjectively ( e.g. White and O'Connell 1993 ) or using relative metrics , such as perplexity with respect to other models ( Brown et al. 1993b ) .


The three preprocessing steps ( tokenization , POS-tagging , lemmatization ) are performed using TreeTagger ( Schmid , 1995 ) .


Many statistical parsers ( Ratnaparkhi , 1999 ; Collins , 1999 ; Charniak , 2001 ) are based on a history-based probability model ( Black et al. , 1993 ) , where the probability of each decision in a parse is conditioned on the previous decisions in the parse .


In informal experiments described elsewhere ( Melamed 1995 ) , I found that the G2 statistic suggested by Dunning ( 1993 ) slightly outperforms 02 .


For right-branching structures , the leftcorner ancestor is the parent , conditioning on which has been found to be beneficial ( Johnson , 1998 ) , as has conditioning on the left-corner child ( Roark and Johnson , 1999 ) .


This strategy is certainly the right one to start out with , since anaphora is always the more typical direction of reference in English prose ( Halliday and Hasan 1976 , p. 329 ) .


This indicates that parse trees are usually not the optimal choice for training tree-based translation models ( Wang et al. , 2010 ) .


In Charniak ( 1996 ) and Krotov et al. ( 1998 ) , it was observed that treebank grammars ( CFGs extracted from treebanks ) are very large and grow with the size of the treebank .


For example , the forward-backward algorithm ( Baum , 1972 ) trains only Hidden Markov Models , while ( Ristad and Yianilos , 1996 ) trains only stochastic edit distance .


ment ( Sarkar and Wintner , 1999 ; Doran et al. , 2000 ; Makino et al. , 1998 ) .


Manning ( 1993 ) argues that , aside from missing domain-specific complementation trends , dictionaries produced by hand will tend to lag behind real language use because of their static nature .


Finally , the Natural Language Toolkit ( NLTK ) is a package of NLP components implemented in Python ( Loper and Bird , 2002 ) .


Politically-oriented text Sentiment analysis has specifically been proposed as a key enabling technology in eRulemaking , allowing the automatic analysis of the opinions that people submit ( Shulman et al. , 2005 ; Cardie et al. , 2006 ; Kwon et al. , 2006 ) .


Burkett and Klein ( 2008 ) and Burkett et al. ( 2010 ) focused on joint parsing and alignment .


But the general outlines are reasonably clear , and we can adapt some of the UDRS ( Reyle 1995 ) work to our own framework .


KUbler , McDonald , and Nivre ( 2009 ) describe a `` typical '' MaltParser model configuration of attributes and features .13 Starting with it , in a series of initial controlled experiments , we settled on using buf [ 0-1 ] + stk [ 0-1 ] for word-forms , and buf [ 0-3 ] + stk [ 0-2 ] for POS tags .


For this evaluation , we randomly selected 50 abstracts with disorders indexed as the main topic from abstracts retrieved using PubMed on the five clinical questions described in Sneiderman et al. ( 2005 ) .


The need for information systems to support physicians at the point of care has been well studied ( Covell et al. , 1985 ; Gorman et al. , 1994 ; Ely et al. , 2005 ) .


This approach is taken in computational syntactic grammars ( e.g. Jensen 1986 ) ; the number of unlikely parses is severely reduced whenever possible , but no attempt is made to define only the so-called grammatical strings of a language .


Previous work on Chinese SRL mainly focused on how to transplant the machine learning methods which has been successful with English , such as Sun and Jurafsky ( 2004 ) , Xue and Palmer ( 2005 ) and Xue ( 2008 ) .


For example , the interaction of lexical rules is explored at run-time , even though the possible interaction can be determined at compile-time given the information available in the lexical rules and the base lexical entries .2 Based on the research results reported in Meurers and Minnen ( 1995 , 1996 ) , we propose a new computational treatment of lexical rules that overcomes these shortcomings and results in a more efficient processing of lexical rules as used in HPSG .


`` Coherence , '' as outlined above , can be understood as a declarative ( or static ) version of marker passing ( Hirst 1987 ; Charniak 1983 ) , with one difference : the activation spreads to theories that share a predicate , not through the IS-A hierarchy , and is limited to elementary facts about predicates appearing in the text .


On small data sets all of the Bayesian estimators strongly outperform EM ( and , to a lesser extent , VB ) with respect to all of our evaluation measures , confirming the results reported in Goldwater and Griffiths ( 2007 ) .


In addition , the advantages of using linguistically annotated data over raw data are well documented ( Mair , 2005 ; Granger and Rayson , 1998 ) .


For the A * algorithm ( Hart et al. 1968 ) as applied to speech recognition , the actual path score is typically augmented with an estimated score for the unseen portion .


Robust natural language understanding in Atlas-Andes is provided by RosÃ© 's CARMEL system ( RosÃ© 2000 ) ; it uses the spelling correction algorithm devised by Elmi and Evens ( 1998 ) .


The framework represents a generalization of several predecessor NLG systems based on Meaning-Text Theory : FoG ( Kittredge and Polguere , 1991 ) , LFS ( Iordanskaja et al. , 1992 ) , and JOYCE ( Rambow and Korelsky , 1992 ) .


Nevertheless , Juola ( 1998 , page 23 ) observes that `` a slightly more general mapping , where two adjacent terminal symbols can be merged into a single lexical item ( for example , a word and its case-marking ) , can capture this sort of result quite handily . ''


Other similar approaches include those of Cicekli and G Â¨ uvenir ( 1996 ) , McTait and Trujillo ( 1999 ) , Carl ( 1999 ) , and Brown ( 2000 ) , inter alia .


( Watanabe et al. , 2007 ; Chiang et al. , 2008 ; Hopkins and May , 2011 ) proposed other optimization objectives by introducing a margin-based and ranking-based indirect loss functions .


Burkett and Klein ( 2012 ) utilized a transformation-based method to learn a sequence of monolingual tree transformations for translation .


Baseline language model : For P0 we used a trigram with modified kneser-ney smoothing [ Chen and Goodman , 1998 ] , which is still considered one of the best smoothing methods for n-gram language models .


Therefore , we preprocess Ontonote-5 .0 to derive mention heads using Collins head rules ( Collins , 1999 ) with gold constituency parsing information and gold named entity information .


Our most accurate single grammar achieves an F score of 91.6 on the WSJ test set , rivaling discriminative reranking approaches ( Charniak and Johnson , 2005 ) and products of latent variable grammars ( Petrov , 2010 ) , despite being a single generative PCFG .


We have presented an ensemble approach to word sense disambiguation ( Pedersen , 2000 ) where multiple Naive Bayesian classifiers , each based on co -- occurrence features from varying sized windows of context , is shown to perform well on the widely studied nouns interest and line .


Over the last decade there has been a lot of interest in developing tutorial dialogue systems that understand student explanations ( Jordan et al. , 2006 ; Graesser et al. , 1999 ; Aleven et al. , 2001 ; Buckley and Wolska , 2007 ; Nielsen et al. , 2008 ; VanLehn et al. , 2007 ) , because high percentages of selfexplanation and student contentful talk are known to be correlated with better learning in humanhuman tutoring ( Chi et al. , 1994 ; Litman et al. , 2009 ; Purandare and Litman , 2008 ; Steinhauser et al. , 2007 ) .


We shall see this in the next example : two sentences , regarded as a fragment of paragraph , are a variation on a theme by Hobbs ( 1979 ) .


Nevertheless , the full document text is present in most systems , sometimes as the only feature ( Sugiyama and Okumura , 2007 ) and sometimes in combination with others see for instance ( Chen and Martin , 2007 ; Popescu and Magnini , 2007 ) - .


The recognizer for these systems is the SUMMIT system ( Zue et al. 1989 ) , which uses a segmental-based framework and includes an auditory model in the front-end processing .


Some recent GRE algorithms have done away with the separation between content determination and linguistic realization , interleaving the two processes instead ( Stone and Webber 1998 ; Krahmer and Theune 2002 ) .


To sample from our proposal distribution , we use a blocked Gibbs sampler based on the one proposed by Goodman ( 1998 ) and used by Johnson et al. ( 2007 ) that samples entire parse trees .


Semantic construction proceeds from the derived tree ( Gardent and Kallmeyer , 2003 ) rather than -- as is more common in TAG -- from the derivation tree .


It allows the construction of a non-TAL ( Shieber , 1994 ) , ( Harbusch & Poller , 2000 ) .


Following previous work ( e.g. , Soon et al. ( 2001 ) and Ponzetto and Strube ( 2006 ) ) , we generate training instances as follows : a positive instance is created for each anaphoric NP , NPj , and its closest antecedent , NPi ; and a negative instance is created for NPj paired with each of the intervening NPs , NPi +1 , NPi +2 , ... , NPj_1 .


TF-IDF ( term frequency-inverse document frequency ) is one of the widely used feature selection techniques in information retrieval ( Yates and Neto , 1999 ) .


The gap mechanism resembles the Hold register idea of ATNs ( Woods 1970 ) and the treatment of bounded domination metavariables in lexical functional grammars ( LFGs ) ( Bresnan 1982 , p. 235 ff . )


To solve these scaling issues , we implement Online Variational Bayesian Inference ( Hoffman et al. , 2010 ; Hoffman et al. , 2012 ) for our models .