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Die Bedeutung des philosophischen Programms John McDowells, das schon in der theoretischen Philosophie eine revolutionäre Neuausrichtung vornimmt, kann erst voll erkannt werden, wenn man auch seine Konsequenzen für die praktische Philosophie in den Blick nimmt. Zwar geht Geist und Welt primär von Dilemmata der Erkenntnistheorie aus. Aus McDowells Vorschlag, die Gleichsetzung der äußeren Natur mit dem bedeutungsfreien Raum der Naturgesetze zugunsten einer Konzeption von Gründen in der Welt aufzugeben, ergibt sich aber die Möglichkeit einer so neuartigen Perspektive auf die Natur moralischer Urteile, dass es fast so scheint, als sei McDowells theoretisches Programm auf diesen Gewinn für die praktische Philosophie hin angelegt worden.
Impurismus ist eine uralte Weltanschauung und eine alte Poetik. Beides habe ich in meinem Buch von 2007 Illustrierte Poetik des Impurismus ausführlich dargestellt. Da ich mich nicht wiederholen will, kann ich die umfangreichen Funde zum Thema hier nicht erneut vortragen. Andererseits soll der Leser dieser Fortsetzung nicht ganz unvorbereitet in die Materie einsteigen. Deshalb will ich einige nackte Fakten als Erinnerung hier zusammenstellen, muß aber doch dringend auf die anschaulichen Grundlagen in dem genannten Buch verweisen, sonst verschreckt die in aller Kürze vorgetragene Ungeheuerlichkeit der ganzen Entdeckung manchen willigen Leser. ...
Wir Philologen haben gut reden. Wir sehen zu, wie andere, die zumeist nicht zu unserer Zunft gehören, die unübersehbare Fülle von Geschriebenem aus seiner jeweiligen Ursprache in alle möglichen Sprachen bringen, und wir verhalten uns dazu als interessierte Zuschauer. Wir haben allen Grund, uns daran zu freuen: Ohne diesen grenzüberschreitenden Waren- und Gedankentausch bliebe das Feld, auf dem wir grasen, enger und parzellierter, als es nach der Intention der Autoren und auch der Sache nach sein müsste. Wir können (sofern wir den nötigen Überblick haben) das loben, was die Übersetzer zu Wege gebracht haben: die Entsprechungen, die sie entdeckt oder erfunden haben, die Kraft, Geschmeidigkeit und Modulationsvielfalt, die sie in ihren Zielsprachen mit Tausenden von einleuchtenden Funden oder mit dem ganzen Ton und Duktus ihrer Übersetzungen erst aktiviert haben. Wenn wir es uns zutrauen, können wir ihnen ins Handwerk pfuschen und einzelne Stellen oder ganze Werke selber übersetzen. Wir können sie kritisieren, wo uns die vorgelegten Übersetzungen zu matt erscheinen oder wo sie sachlich oder stilistisch mehr als nötig ‚hinter dem Original zurückbleiben; wir können Verbesserungsvorschläge machen. Wenn wir Übersetzungen zitieren und es nötig finden, sie abzuwandeln, bewegen wir uns in einer Grauzone zwischen dem Respekt vor dem Übersetzer, der Lust an noch weiteren erkannten Potenzen des Textes und dem Drang, möglichst ‚alles, was wir aus dem Original herausgelesen haben, in der eigenen Sprache den Hörern oder Lesern nahezubringen.
Römische Bildnisse : Bibliographie, ungekürzt, mit den zu ergänzenden Literaturverweisen des Autors
(2010)
Originalfassung der in der Verlagspublikation um zahlreiche Literaturverweise gekürzten Bibliographie des Werkes: Götz Lahusen: Römische Bildnisse : Auftraggeber, Funktionen, Standorte. - Mainz : von Zabern, 2010. - Lizenz der WBG (Wiss. Buchges.) Darmstadt. - ISBN: 978-3-8053-3738-0. Pp. : EUR 49.90
In seinen Sammlungen bildet das Deutsche Literaturarchiv Marbach (DLA) das Netzwerk des literarischen Lebens in all seinen Facetten ab. Im Zentrum des quellenorientierten Sammelns und der Erschließung steht der Autor (bzw. die Autorin). Die Literatur wird dokumentiert vom Entstehungsprozess eines Werkes über die verschiedenen Ausgaben und dessen Rezeption in der Literaturkritik, seine dramaturgische Umsetzung in Hörfunk, Film, auf der Bühne und in der Musik. Seit 2008 bezieht das DLA auch Internetquellen wie literarische Zeitschriften, Netzliteratur und Weblogs in sein Spektrum mit ein und reagiert damit auf die zunehmende Bedeutung des Internets als Publikationsforum. Sammeln, Erschließen und Archivieren bilden eine notwendige Einheit; gerade die Flüchtigkeit der netzbasierten Ressourcen macht eine langfristige Sicherung der Verfügbarkeit erforderlich. Notwendig sind daher mehrere Säulen, auf denen diese neue Sammlung von „Literatur im Netz“ basiert.
Nous présentons ici différents algorithmes d’analyse pour grammaires à concaténation d’intervalles (Range Concatenation Grammar, RCG), dont un nouvel algorithme de type Earley, dans le paradigme de l’analyse déductive. Notre travail est motivé par l’intérêt porté récemment à ce type de grammaire, et comble un manque dans la littérature existante.
Multicomponent Tree Adjoining Grammars (MCTAGs) are a formalism that has been shown to be useful for many natural language applications. The definition of non-local MCTAG however is problematic since it refers to the process of the derivation itself: a simultaneity constraint must be respected concerning the way the members of the elementary tree sets are added. Looking only at the result of a derivation (i.e., the derived tree and the derivation tree), this simultaneity is no longer visible and therefore cannot be checked. I.e., this way of characterizing MCTAG does not allow to abstract away from the concrete order of derivation. In this paper, we propose an alternative definition of MCTAG that characterizes the trees in the tree language of an MCTAG via the properties of the derivation trees (in the underlying TAG) the MCTAG licences. We provide similar characterizations for various types of MCTAG. These characterizations give a better understanding of the formalisms, they allow a more systematic comparison of different types of MCTAG, and, furthermore, they can be exploited for parsing.
This paper investigates the class of Tree-Tuple MCTAG with Shared Nodes, TT-MCTAG for short, an extension of Tree Adjoining Grammars that has been proposed for natural language processing, in particular for dealing with discontinuities and word order variation in languages such as German. It has been shown that the universal recognition problem for this formalism is NP-hard, but so far it was not known whether the class of languages generated by TT-MCTAG is included in PTIME. We provide a positive answer to this question, using a new characterization of TT-MCTAG.
We present a CYK and an Earley-style algorithm for parsing Range Concatenation Grammar (RCG), using the deductive parsing framework. The characteristic property of the Earley parser is that we use a technique of range boundary constraint propagation to compute the yields of non-terminals as late as possible. Experiments show that, compared to previous approaches, the constraint propagation helps to considerably decrease the number of items in the chart.
In this paper, we argue that difficulties in the definition of coreference itself contribute to lower inter-annotator agreement in certain cases. Data from a large referentially annotated corpus serves to corroborate this point, using a quantitative investigation to assess which effects or problems are likely to be the most prominent. Several examples where such problems occur are discussed in more detail, and we then propose a generalisation of Poesio, Reyle and Stevenson’s Justified Sloppiness Hypothesis to provide a unified model for these cases of disagreement and argue that a deeper understanding of the phenomena involved allows to tackle problematic cases in a more principled fashion than would be possible using only pre-theoretic intuitions.
Traditionally, parsers are evaluated against gold standard test data. This can cause problems if there is a mismatch between the data structures and representations used by the parser and the gold standard. A particular case in point is German, for which two treebanks (TiGer and TüBa-D/Z) are available with highly different annotation schemes for the acquisition of (e.g.) PCFG parsers. The differences between the TiGer and TüBa-D/Z annotation schemes make fair and unbiased parser evaluation difficult [7, 9, 12]. The resource (TEPACOC) presented in this paper takes a different approach to parser evaluation: instead of providing evaluation data in a single annotation scheme, TEPACOC uses comparable sentences and their annotations for 5 selected key grammatical phenomena (with 20 sentences each per phenomena) from both TiGer and TüBa-D/Z resources. This provides a 2 times 100 sentence comparable testsuite which allows us to evaluate TiGer-trained parsers against the TiGer part of TEPACOC, and TüBa-D/Z-trained parsers against the TüBa-D/Z part of TEPACOC for key phenomena, instead of comparing them against a single (and potentially biased) gold standard. To overcome the problem of inconsistency in human evaluation and to bridge the gap between the two different annotation schemes, we provide an extensive error classification, which enables us to compare parser output across the two different treebanks. In the remaining part of the paper we present the testsuite and describe the grammatical phenomena covered in the data. We discuss the different annotation strategies used in the two treebanks to encode these phenomena and present our error classification of potential parser errors.
Parsing coordinations
(2009)
The present paper is concerned with statistical parsing of constituent structures in German. The paper presents four experiments that aim at improving parsing performance of coordinate structure: 1) reranking the n-best parses of a PCFG parser, 2) enriching the input to a PCFG parser by gold scopes for any conjunct, 3) reranking the parser output for all possible scopes for conjuncts that are permissible with regard to clause structure. Experiment 4 reranks a combination of parses from experiments 1 and 3. The experiments presented show that n- best parsing combined with reranking improves results by a large margin. Providing the parser with different scope possibilities and reranking the resulting parses results in an increase in F-score from 69.76 for the baseline to 74.69. While the F-score is similar to the one of the first experiment (n-best parsing and reranking), the first experiment results in higher recall (75.48% vs. 73.69%) and the third one in higher precision (75.43% vs. 73.26%). Combining the two methods results in the best result with an F-score of 76.69.
Distributional approximations to lexical semantics are very useful not only in helping the creation of lexical semantic resources (Kilgariff et al., 2004; Snow et al., 2006), but also when directly applied in tasks that can benefit from large-coverage semantic knowledge such as coreference resolution (Poesio et al., 1998; Gasperin and Vieira, 2004; Versley, 2007), word sense disambiguation (Mc- Carthy et al., 2004) or semantical role labeling (Gordon and Swanson, 2007). We present a model that is built from Webbased corpora using both shallow patterns for grammatical and semantic relations and a window-based approach, using singular value decomposition to decorrelate the feature space which is otherwise too heavily influenced by the skewed topic distribution of Web corpora.
This paper investigates the relation between TT-MCTAG, a formalism used in computational linguistics, and RCG. RCGs are known to describe exactly the class PTIME; simple RCG even have been shown to be equivalent to linear context-free rewriting systems, i.e., to be mildly context-sensitive. TT-MCTAG has been proposed to model free word order languages. In general, it is NP-complete. In this paper, we will put an additional limitation on the derivations licensed in TT-MCTAG. We show that TT-MCTAG with this additional limitation can be transformed into equivalent simple RCGs. This result is interesting for theoretical reasons (since it shows that TT-MCTAG in this limited form is mildly context-sensitive) and, furthermore, even for practical reasons: We use the proposed transformation from TT-MCTAG to RCG in an actual parser that we have implemented.
The ACL 2008 Workshop on Parsing German features a shared task on parsing German. The goal of the shared task was to find reasons for the radically different behavior of parsers on the different treebanks and between constituent and dependency representations. In this paper, we describe the task and the data sets. In addition, we provide an overview of the test results and a first analysis.
The problem of vocalization, or diacritization, is essential to many tasks in Arabic NLP. Arabic is generally written without the short vowels, which leads to one written form having several pronunciations with each pronunciation carrying its own meaning(s). In the experiments reported here, we define vocalization as a classification problem in which we decide for each character in the unvocalized word whether it is followed by a short vowel. We investigate the importance of different types of context. Our results show that the combination of using memory-based learning with only a word internal context leads to a word error rate of 6.64%. If a lexical context is added, the results deteriorate slowly.
How to compare treebanks
(2008)
Recent years have seen an increasing interest in developing standards for linguistic annotation, with a focus on the interoperability of the resources. This effort, however, requires a profound knowledge of the advantages and disadvantages of linguistic annotation schemes in order to avoid importing the flaws and weaknesses of existing encoding schemes into the new standards. This paper addresses the question how to compare syntactically annotated corpora and gain insights into the usefulness of specific design decisions. We present an exhaustive evaluation of two German treebanks with crucially different encoding schemes. We evaluate three different parsers trained on the two treebanks and compare results using EVALB, the Leaf-Ancestor metric, and a dependency-based evaluation. Furthermore, we present TePaCoC, a new testsuite for the evaluation of parsers on complex German grammatical constructions. The testsuite provides a well thought-out error classification, which enables us to compare parser output for parsers trained on treebanks with different encoding schemes and provides interesting insights into the impact of treebank annotation schemes on specific constructions like PP attachment or non-constituent coordination.
Part-of-Speech tagging is generally performed by Markov models, based on bigram or trigram models. While Markov models have a strong concentration on the left context of a word, many languages require the inclusion of right context for correct disambiguation. We show for German that the best results are reached by a combination of left and right context. If only left context is available, then changing the direction of analysis and going from right to left improves the results. In a version of MBT (Daelemans et al., 1996) with default parameter settings, the inclusion of the right context improved POS tagging accuracy from 94.00% to 96.08%, thus corroborating our hypothesis. The version with optimized parameters reaches 96.73%.
This article presents linguistic features of and educational approaches to a new variety of German that has emerged in multi-ethnic urban areas in Germany: Kiezdeutsch (‘Hood German’). From a linguistic point of view, Kiezdeutsch is very interesting, as it is a multi-ethnolect that combines features of a youth language with those of a contact language. We will present examples that illustrate the grammatical productivity and innovative potential of this variety. From an educational perspective, Kiezdeutsch has also a high potential in many respects: school projects can help enrich intercultural communication and weaken derogatory attitudes. In grammar lessons, Kiezdeutsch can be a means to enhance linguistic competence by having the adolescents analyse their own language. Keywords: German, Kiezdeutsch, multi-ethnolect, migrants’ language, language change, educational proposals
Cet article étudie la relation entre les grammaires darbres adjoints à composantes multiples avec tuples darbres (TT-MCTAG), un formalisme utilisé en linguistique informatique, et les grammaires à concaténation dintervalles (RCG). Les RCGs sont connues pour décrire exactement la classe PTIME, il a en outre été démontré que les RCGs « simples » sont même équivalentes aux systèmes de réécriture hors-contextes linéaires (LCFRS), en dautres termes, elles sont légèrement sensibles au contexte. TT-MCTAG a été proposé pour modéliser les langages à ordre des mots libre. En général ces langages sont NP-complets. Dans cet article, nous définissons une contrainte additionnelle sur les dérivations autorisées par le formalisme TT-MCTAG. Nous montrons ensuite comment cette forme restreinte de TT-MCTAG peut être convertie en une RCG simple équivalente. Le résultat est intéressant pour des raisons théoriques (puisqu’il montre que la forme restreinte de TT-MCTAG est légèrement sensible au contexte), mais également pour des raisons pratiques (la transformation proposée ici a été utilisée pour implanter un analyseur pour TT-MCTAG).
Die unten folgende Stellungnahme wurde dem Herausgeber der Zeitschrift für deutsches Altertum und deutsche Literatur angeboten, um eine Reihe von gravierenden Missverständnissen eines Rezensenten (Jürgen Schulz-Grobert) auszuräumen, die dieser in seiner Besprechung des zweiten Bandes der Sämtlichen Werke Johann Fischarts der Fachwelt gegenüber erkennen ließ. Der Herausgeber der Zeitschrift verweigerte sich einer Diskussion und lehnte den Abdruck unserer Entgegnung ab. Dies ist umso bedauerlicher, als uns der Rezensent den Vorwurf gemacht hat, unsere "Diskussionsbereitschaft [...] [sei] auch in anderen entscheidenden Fragen ausgesprochen begrenzt", was immer er damit meint.
In this paper, we present an open-source parsing environment (Tübingen Linguistic Parsing Architecture, TuLiPA) which uses Range Concatenation Grammar (RCG) as a pivot formalism, thus opening the way to the parsing of several mildly context-sensitive formalisms. This environment currently supports tree-based grammars (namely Tree-Adjoining Grammars (TAG) and Multi-Component Tree-Adjoining Grammars with Tree Tuples (TT-MCTAG)) and allows computation not only of syntactic structures, but also of the corresponding semantic representations. It is used for the development of a tree-based grammar for German.
TT-MCTAG lets one abstract away from the relative order of co-complements in the final derived tree, which is more appropriate than classic TAG when dealing with flexible word order in German. In this paper, we present the analyses for sentential complements, i.e., wh-extraction, thatcomplementation and bridging, and we work out the crucial differences between these and respective accounts in XTAG (for English) and V-TAG (for German).
Developing linguistic resources, in particular grammars, is known to be a complex task in itself, because of (amongst others) redundancy and consistency issues. Furthermore some languages can reveal themselves hard to describe because of specific characteristics, e.g. the free word order in German. In this context, we present (i) a framework allowing to describe tree-based grammars, and (ii) an actual fragment of a core multicomponent tree-adjoining grammar with tree tuples (TT-MCTAG) for German developed using this framework. This framework combines a metagrammar compiler and a parser based on range concatenation grammar (RCG) to respectively check the consistency and the correction of the grammar. The German grammar being developed within this framework already deals with a wide range of scrambling and extraction phenomena.
In this paper we present a parsing architecture that allows processing of different mildly context-sensitive formalisms, in particular Tree-Adjoining Grammar (TAG), Multi-Component Tree-Adjoining Grammar with Tree Tuples (TT-MCTAG) and simple Range Concatenation Grammar (RCG). Furthermore, for tree-based grammars, the parser computes not only syntactic analyses but also the corresponding semantic representations.
Recent approaches to Word Sense Disambiguation (WSD) generally fall into two classes: (1) information-intensive approaches and (2) information-poor approaches. Our hypothesis is that for memory-based learning (MBL), a reduced amount of data is more beneficial than the full range of features used in the past. Our experiments show that MBL combined with a restricted set of features and a feature selection method that minimizes the feature set leads to competitive results, outperforming all systems that participated in the SENSEVAL-3 competition on the Romanian data. Thus, with this specific method, a tightly controlled feature set improves the accuracy of the classifier, reaching 74.0% in the fine-grained and 78.7% in the coarse-grained evaluation.
Prepositional phrase (PP) attachment is one of the major sources for errors in traditional statistical parsers. The reason for that lies in the type of information necessary for resolving structural ambiguities. For parsing, it is assumed that distributional information of parts-of-speech and phrases is sufficient for disambiguation. For PP attachment, in contrast, lexical information is needed. The problem of PP attachment has sparked much interest ever since Hindle and Rooth (1993) formulated the problem in a way that can be easily handled by machine learning approaches: In their approach, PP attachment is reduced to the decision between noun and verb attachment; and the relevant information is reduced to the two possible attachment sites (the noun and the verb) and the preposition of the PP. Brill and Resnik (1994) extended the feature set to the now standard 4-tupel also containing the noun inside the PP. Among many publications on the problem of PP attachment, Volk (2001; 2002) describes the only system for German. He uses a combination of supervised and unsupervised methods. The supervised method is based on the back-off model by Collins and Brooks (1995), the unsupervised part consists of heuristics such as ”If there is a support verb construction present, choose verb attachment”. Volk trains his back-off model on the Negra treebank (Skut et al., 1998) and extracts frequencies for the heuristics from the ”Computerzeitung”. The latter also serves as test data set. Consequently, it is difficult to compare Volk’s results to other results for German, including the results presented here, since not only he uses a combination of supervised and unsupervised learning, but he also performs domain adaptation. Most of the researchers working on PP attachment seem to be satisfied with a PP attachment system; we have found hardly any work on integrating the results of such approaches into actual parsers. The only exceptions are Mehl et al. (1998) and Foth and Menzel (2006), both working with German data. Mehl et al. report a slight improvement of PP attachment from 475 correct PPs out of 681 PPs for the original parser to 481 PPs. Foth and Menzel report an improvement of overall accuracy from 90.7% to 92.2%. Both integrate statistical attachment preferences into a parser. First, we will investigate whether dependency parsing, which generally uses lexical information, shows the same performance on PP attachment as an independent PP attachment classifier does. Then we will investigate an approach that allows the integration of PP attachment information into the output of a parser without having to modify the parser: The results of an independent PP attachment classifier are integrated into the parse of a dependency parser for German in a postprocessing step.
This paper presents an LTAG analysis of reflexives like himself and reciprocals like each other. These items need to find a c-commanding antecedent from which they retrieve (part of) their own denotation and with which they syntactically agree. The relation between anaphoric item and antecendent must satisfy the following important locality conditions (Chomsky (1981)).
In this paper, we will argue for a novel analysis of the auxiliary alternation in Early English, its development and subsequent loss which has broader consequences for the way that auxiliary selection is looked at cross-linguistically. We will present evidence that the choice of auxiliaries accompanying past participles in Early English differed in several significant respects from that in the familiar modern European languages. Specifically, while the construction with have became a full-fledged perfect by some time in the ME period, that with be was actually a stative resultative, which it remained until it was lost. We will show that this accounts for some otherwise surprising restrictions on the distribution of BE in Early English and allows a better understanding of the spread of HAVE through late ME and EModE. Perhaps more importantly, the Early English facts also provide insight into the genesis of the kind of auxiliary selection found in German, Dutch and Italian. Our analysis of them furthermore suggests a promising strategy for explaining cross-linguistic variation in auxiliary selection in terms of variation in the syntactico-semantic structure of the perfect. In this introductory section, we will first provide some background on the historical situation we will be discussing, then we will lay out the main claims for which we will be arguing in the paper.
In this paper, we introduce an extension of the XMG system (eXtensibleMeta-Grammar) in order to allow for the description of Multi-Component Tree Adjoining Grammars. In particular, we introduce the XMG formalism and its implementation, and show how the latter makes it possible to extend the system relatively easily to different target formalisms, thus opening the way towards multi-formalism.
We adopt Markert and Nissim (2005)’s approach of using the World Wide Web to resolve cases of coreferent bridging for German and discuss the strength and weaknesses of this approach. As the general approach of using surface patterns to get information on ontological relations between lexical items has only been tried on English, it is also interesting to see whether the approach works for German as well as it does for English and what differences between these languages need to be accounted for. We also present a novel approach for combining several patterns that yields an ensemble that outperforms the best-performing single patterns in terms of both precision and recall.
Multicomponent Tree Adjoining Grammars (MCTAG) is a formalism that has been shown to be useful for many natural language applications. The definition of MCTAG however is problematic since it refers to the process of the derivation itself: a simultaneity constraint must be respected concerning the way the members of the elementary tree sets are added. This way of characterizing MCTAG does not allow to abstract away from the concrete order of derivation. In this paper, we propose an alternative definition of MCTAG that characterizes the trees in the tree language of an MCTAG via the properties of the derivation trees (in the underlying TAG) the MCTAG licences. This definition gives a better understanding of the formalism, it allows a more systematic comparison of different types of MCTAG, and, furthermore, it can be exploited for parsing.
In this paper, we investigate the usefulness of a wide range of features for their usefulness in the resolution of nominal coreference, both as hard constraints (i.e. completely removing elements from the list of possible candidates) as well as soft constraints (where a cumulation of violations of soft constraints will make it less likely that a candidate is chosen as the antecedent). We present a state of the art system based on such constraints and weights estimated with a maximum entropy model, using lexical information to resolve cases of coreferent bridging.
The work presented here addresses the question of how to determine whether a grammar formalism is powerful enough to describe natural languages. The expressive power of a formalism can be characterized in terms of i) the string languages it generates (weak generative capacity (WGC)) or ii) the tree languages it generates (strong generative capacity (SGC)). The notion of WGC is not enough to determine whether a formalism is adequate for natural languages. We argue that even SGC is problematic since the sets of trees a grammar formalism for natural languages should be able to generate is difficult to determine. The concrete syntactic structures assumed for natural languages depend very much on theoretical stipulations and empirical evidence for syntactic structures is rather hard to obtain. Therefore, for lexicalized formalisms, we propose to consider the ability to generate certain strings together with specific predicate argument dependencies as a criterion for adequacy for natural languages.
This paper presents an approach to the question whether it is possible to construct a parser based on ideas from case-based reasoning. Such a parser would employ a partial analysis of the input sentence to select a (nearly) complete syntax tree and then adapt this tree to the input sentence. The experiments performed on German data from the Tüba-D/Z treebank and the KaRoPars partial parser show that a wide range of levels of generality can be reached, depending on which types of information are used to determine the similarity between input sentence and training sentences. The results are such that it is possible to construct a case-based parser. The optimal setting out of those presented here need to be determined empirically.
In recent years, research in parsing has extended in several new directions. One of these directions is concerned with parsing languages other than English. Treebanks have become available for many European languages, but also for Arabic, Chinese, or Japanese. However, it was shown that parsing results on these treebanks depend on the types of treebank annotations used. Another direction in parsing research is the development of dependency parsers. Dependency parsing profits from the non-hierarchical nature of dependency relations, thus lexical information can be included in the parsing process in a much more natural way. Especially machine learning based approaches are very successful (cf. e.g.). The results achieved by these dependency parsers are very competitive although comparisons are difficult because of the differences in annotation. For English, the Penn Treebank has been converted to dependencies. For this version, Nivre et al. report an accuracy rate of 86.3%, as compared to an F-score of 92.1 for Charniaks parser. The Penn Chinese Treebank is also available in a constituent and a dependency representations. The best results reported for parsing experiments with this treebank give an F-score of 81.8 for the constituent version and 79.8% accuracy for the dependency version. The general trend in comparisons between constituent and dependency parsers is that the dependency parser performs slightly worse than the constituent parser. The only exception occurs for German, where F-scores for constituent plus grammatical function parses range between 51.4 and 75.3, depending on the treebank, NEGRA or TüBa-D/Z. The dependency parser based on a converted version of Tüba-D/Z, in contrast, reached an accuracy of 83.4%, i.e. 12 percent points better than the best constituent analysis including grammatical functions.
This paper presents a comparative study of probabilistic treebank parsing of German, using the Negra and TüBa-D/Z treebanks. Experiments with the Stanford parser, which uses a factored PCFG and dependency model, show that, contrary to previous claims for other parsers, lexicalization of PCFG models boosts parsing performance for both treebanks. The experiments also show that there is a big difference in parsing performance, when trained on the Negra and on the TüBa-D/Z treebanks. Parser performance for the models trained on TüBa-D/Z are comparable to parsing results for English with the Stanford parser, when trained on the Penn treebank. This comparison at least suggests that German is not harder to parse than its West-Germanic neighbor language English.
Using a qualitative analysis of disagreements from a referentially annotated newspaper corpus, we show that, in coreference annotation, vague referents are prone to greater disagreement. We show how potentially problematic cases can be dealt with in a way that is practical even for larger-scale annotation, considering a real-world example from newspaper text.
In the past, a divide could be seen between ’deep’ parsers on the one hand, which construct a semantic representation out of their input, but usually have significant coverage problems, and more robust parsers on the other hand, which are usually based on a (statistical) model derived from a treebank and have larger coverage, but leave the problem of semantic interpretation to the user. More recently, approaches have emerged that combine the robustness of datadriven (statistical) models with more detailed linguistic interpretation such that the output could be used for deeper semantic analysis. Cahill et al. (2002) use a PCFG-based parsing model in combination with a set of principles and heuristics to derive functional (f-)structures of Lexical-Functional Grammar (LFG). They show that the derived functional structures have a better quality than those generated by a parser based on a state-of-the-art hand-crafted LFG grammar. Advocates of Dependency Grammar usually point out that dependencies already are a semantically meaningful representation (cf. Menzel, 2003). However, parsers based on dependency grammar normally create underspecified representations with respect to certain phenomena such as coordination, apposition and control structures. In these areas they are too "shallow" to be directly used for semantic interpretation. In this paper, we adopt a similar approach to Cahill et al. (2002) using a dependency-based analysis to derive functional structure, and demonstrate the feasibility of this approach using German data. A major focus of our discussion is on the treatment of coordination and other potentially underspecified structures of the dependency data input. F-structure is one of the two core levels of syntactic representation in LFG (Bresnan, 2001). Independently of surface order, it encodes abstract syntactic functions that constitute predicate argument structure and other dependency relations such as subject, predicate, adjunct, but also further semantic information such as the semantic type of an adjunct (e.g. directional). Normally f-structure is captured as a recursive attribute value matrix, which is isomorphic to a directed graph representation. Figure 5 depicts an example target f-structure. As mentioned earlier, these deeper-level dependency relations can be used to construct logical forms as in the approaches of van Genabith and Crouch (1996), who construct underspecified discourse representations (UDRSs), and Spreyer and Frank (2005), who have robust minimal recursion semantics (RMRS) as their target representation. We therefore think that f-structures are a suitable target representation for automatic syntactic analysis in a larger pipeline of mapping text to interpretation. In this paper, we report on the conversion from dependency structures to fstructure. Firstly, we evaluate the f-structure conversion in isolation, starting from hand-corrected dependencies based on the TüBa-D/Z treebank and Versley (2005)´s conversion. Secondly, we start from tokenized text to evaluate the combined process of automatic parsing (using Foth and Menzel (2006)´s parser) and f-structure conversion. As a test set, we randomly selected 100 sentences from TüBa-D/Z which we annotated using a scheme very close to that of the TiGer Dependency Bank (Forst et al., 2004). In the next section, we sketch dependency analysis, the underlying theory of our input representations, and introduce four different representations of coordination. We also describe Weighted Constraint Dependency Grammar (WCDG), the dependency parsing formalism that we use in our experiments. Section 3 characterises the conversion of dependencies to f-structures. Our evaluation is presented in section 4, and finally, section 5 summarises our results and gives an overview of problems remaining to be solved.
This paper compares two approaches to computational semantics, namely semantic unification in Lexicalized Tree Adjoining Grammars (LTAG) and Lexical Resource Semantics (LRS) in HPSG. There are striking similarities between the frameworks that make them comparable in many respects. We will exemplify the differences and similarities by looking at several phenomena. We will show, first of all, that many intuitions about the mechanisms of semantic computations can be implemented in similar ways in both frameworks. Secondly, we will identify some aspects in which the frameworks intrinsically differ due to more general differences between the approaches to formal grammar adopted by LTAG and HPSG.
Relative quantifier scope in German depends, in contrast to English, very much on word order. The scope possibilities of a quantifier are determined by its surface position, its base position and the type of the quantifier. In this paper we propose a multicomponent analysis for German quantifiers computing the scope of the quantifier, in particular its minimal nuclear scope, depending on the syntactic configuration it occurs in.
Der Workshop "Nationale Spezifika und internationale Aspekte in der Wissenschaftsentwicklung – unter besonderer Berücksichtigung der Narratologie" soll, so die Organisatoren in ihrer Einladung – "Gelegenheit bieten, Bedingungen und Möglichkeiten integrativer Ansätze zur Untersuchung von Wissenschaftsprozessen zu diskutieren und wichtige Faktoren der Wissenschaftsentwicklung zu benennen und kritisch zu beleuchten." Die Produktion, Distribution und Rezeption von Wissenssystemen vollziehe sich, schreiben die Organisatoren, "in unterschiedlichen nationalen und internationalen sozialen Räumen, die sowohl die Form als auch den kognitiven Gehalt von Theorien mitunter stark mitstrukturieren, ihre Durchsetzung begünstigen oder behindern. Das wird besonders deutlich, wenn man Transferprozesse von Theorien verfolgt." Den Begriff des Wissenstransfers, der hier in Anschlag gebracht wird, möchte ich in meinem Beitrag einer terminologischen Klärung zuführen. Dazu möchte ich zunächst einige terminologische Überlegungen über den Status der Teilbegriffe anstellen, aus denen der Begriff zusammengesetzt ist (I.), dann die Verwendung des Begriffs in verschiedenen disziplinären Kontexten beobachten (II.) und schließlich einen Vorschlag für eine differenzierte Verwendung des Begriffs als Analysekategorie der Wissenschaftsentwicklung machen (III).
In the last decade, the Penn treebank has become the standard data set for evaluating parsers. The fact that most parsers are solely evaluated on this specific data set leaves the question unanswered how much these results depend on the annotation scheme of the treebank. In this paper, we will investigate the influence which different decisions in the annotation schemes of treebanks have on parsing. The investigation uses the comparison of similar treebanks of German, NEGRA and TüBa-D/Z, which are subsequently modified to allow a comparison of the differences. The results show that deleted unary nodes and a flat phrase structure have a negative influence on parsing quality while a flat clause structure has a positive influence.
This paper develops a framework for TAG (Tree Adjoining Grammar) semantics that brings together ideas from different recent approaches.Then, within this framework, an analysis of scope is proposed that accounts for the different scopal properties of quantifiers, adverbs, raising verbs and attitude verbs. Finally, including situation variables in the semantics, different situation binding possibilities are derived for different types of quantificational elements.
This paper profiles significant differences in syntactic distribution and differences in word class frequencies for two treebanks of spoken and written German: the TüBa-D/S, a treebank of transliterated spontaneous dialogs, and the TüBa-D/Z treebank of newspaper articles published in the German daily newspaper ´die tageszeitung´(taz). The approach can be used more generally as a means of distinguishing and classifying language corpora of different genres.
Multicomponent Tree Adjoining Grammars (MCTAG) is a formalism that has been shown to be useful for many natural language applications. The definition of MCTAG however is problematic since it refers to the process of the derivation itself: a simultaneity constraint must be respected concerning the way the members of the elementary tree sets are added. Looking only at the result of a derivation (i.e., the derived tree and the derivation tree), this simultaneity is no longer visible and therefore cannot be checked. I.e., this way of characterizing MCTAG does not allow to abstract away from the concrete order of derivation. Therefore, in this paper, we propose an alternative definition of MCTAG that characterizes the trees in the tree language of an MCTAG via the properties of the derivation trees the MCTAG licences.
When a statistical parser is trained on one treebank, one usually tests it on another portion of the same treebank, partly due to the fact that a comparable annotation format is needed for testing. But the user of a parser may not be interested in parsing sentences from the same newspaper all over, or even wants syntactic annotations for a slightly different text type. Gildea (2001) for instance found that a parser trained on the WSJ portion of the Penn Treebank performs less well on the Brown corpus (the subset that is available in the PTB bracketing format) than a parser that has been trained only on the Brown corpus, although the latter one has only half as many sentences as the former. Additionally, a parser trained on both the WSJ and Brown corpora performs less well on the Brown corpus than on the WSJ one. This leads us to the following questions that we would like to address in this paper: - Is there a difference in usefulness of techniques that are used to improve parser performance between the same-corpus and the different-corpus case? - Are different types of parsers (rule-based and statistical) equally sensitive to corpus variation? To achieve this, we compared the quality of the parses of a hand-crafted constraint-based parser and a statistical PCFG-based parser that was trained on a treebank of German newspaper text.
Der Autor beschäftigt sich u. a. mit den Fragen: Welchen Stellenwert haben unsere literarischen Bildungsgüter in der Mediengesellschaft? Stehen Goethe und Schiller, das Dioskurenpaar der deutschen Klassik, noch fest auf dem Weimarer Sockel, oder zerbröselt dieser zum Sanierungsfall, en passant besucht auf Klassenfahrten, von denen nur das ins heimische Bücherregal wandert, was leicht faßlich ist?
Während der Brief in Zeiten von persönlichen Krisen und Konflikten mancherlei Unannehmlichkeiten aus dem Kommunikationsweg räumt, stellt der Kontext Krieg für das Briefeschreiben in vielerlei Hinsicht eine Herausforderung dar. Der Privatbrief (Epistula familiaris) ist in der ersten Hälfte des 20. Jahrhunderts in Westeuropa – das heisst auch zur Zeit des 2. Weltkriegs – das wichtigste Medium informeller Distanzkommunikation, welche im Allgemeinen durch Inoffizialität und Spontaneität, durch Individualität und Vertraulichkeit gekennzeichnet ist. In der Regel ist der Privatbrief im juristischen Sinne nicht verfügbar. Ein Kennzeichen ist somit auch seine Nichtreproduzierbarkeit. Neben der thematischen Offenheit macht sich meist eine stärkere stilistische Freiheit bemerkbar. Zeichen von Flüchtigkeit oder Sorgfalt sind ausser den Formalia des Datums, der Anrede, des Textkörpers und der Unterschrift, über das geschriebene Wort hinaus nonverbale Informationen wie die Lesbarkeit der Schrift, die Wahl des Papiers, Schreibwerkzeug sowie die Länge eines Briefes (vgl. Ermert 1979, Nickisch 1991, Beyer/ Täubrich 1996, Zott 2003). Der Privatbrief wird zwar im graphischen Medium der Schrift realisiert, steht aber stilistisch der konzeptionellen "Mündlichkeit" näher. (Koch/ Oesterreicher 1994, 587) Der private Briefwechsel wird spontan aufgenommen und kann in der Regel ohne Zwang abgebrochen werden (vgl. Zott 2003). ...
LTAG semantics for questions
(2004)
This papers presents a compositional semantic analysis of interrogatives clauses in LTAG (Lexicalized Tree Adjoining Grammar) that captures the scopal properties of wh- and nonwh-quantificational elements. It is shown that the present approach derives the correct semantics for examples claimed to be problematic for LTAG semantic approaches based on the derivation tree. The paper further provides an LTAG semantics for embedded interrogatives.