Scope Ambiguity Research Articles

Local Tree Description Grammars

This paper addresses the problem of integrating underspecification of the parent (immediate dominance) and the dominance relation into tree-generating grammar formalisms for natural language processing. Retaining the advantages of Tree Adjoining Grammars (TAG), in particular extended domains of locality and a local derivation process, a TAG extension called local Tree Description Grammar (local TDG) is defined that generates tree descriptions. In contrast to earlier tree description based variants of TAG, the possibility of an underspecified dominance relation provides underspecified representations for scope ambiguities. Furthermore, local TDGs allow an adequate treatment of long-distance scrambling in German which is one of the problematic phenomena for TAG.

The Cognitive Nature of Instantiation

People are easily able to infer that a property true of everything must be true of a particular individual and, similarly, that a property true of an individual is also true of something or other. If everything is made of quarks, then George is made of them, and if George is made of quarks, then something is made of them. The three experiments reported here examine how people make inferences like these that require instantiation—from universal terms (e.g., everything) to particular terms (e.g., George), from particular terms to indefinite terms (e.g., something), or from universal terms to indefinite ones. Results from all three experiments show that it takes people longer to recognize the deductive correctness of arguments that depend on two types of instantiation (e.g., from a universal term to a particular term and from a particular term to an indefinite) than those that depend on two examples of the same type. Experiments 1–3 rule out overall abstractness of the premise or the conclusion as the cause of this difference. Experiments 2 and 3 rule out the possibility that the difference is due to repeated noun phrases. Experiment 3 rules out scope ambiguity as the source of the effect. These findings suggest that people use different cognitive operations to instantiate terms and that switching between them takes time and mental effort.

Two kinds of reconstruction

This essay addresses various issues concerning noun phrase interpretation in German. It is argued that the concept of Semantic Reconstruction (Cresti 1995, Rullmann 1995) can be fruitfully employed in the derivation of quantifier scope ambiguities in German. Semantic Reconstruction will be demonstrated to be an independently needed strategy of grammar, that is not parasitic on syntactic reconstruction as expressed by Copy Theory (Chomsky 1992). The basic difference between Semantic Reconstruction and syntactic reconstruction will be traced back to their asymmetric availability in scrambling chains: scrambling can be undone only by Semantic Reconstruction.

The semantics and pragmatics of presupposition

In this paper, we offer a novel analysis of presuppositions, paying particular attention to the interaction between the knowledge resources that are required to interpret them. The analysis has two main features. First, we capture an analogy between presuppositions, anaphora and scope ambiguity (cf. van der Sandt I992), by utilizing semantic underspecification (cf. Reyle I993). Second, resolving this underspecification requires reasoning about how the presupposition is rhetorically connected to the discourse context. This has several consequences. First, since pragmatic information plays a role in computing the rhetorical relation, it also constrains the interpretation of presuppositions. Our account therefore provides a formal framework for analysing problematic data, which require pragmatic reasoning. Second, binding presuppositions to the context via rhetorical links replaces accommodating them, in the sense of adding them to the context (cf. Lewis I979). The treatment of presupposition is thus generalized and integrated into the discourse update procedure. We formalize this approach in SDRT (Asher I993; Lascarides & Asher I993), and demonstrate that it provides a rich framework for interpreting presuppositions, where semantic and pragmatic constraints are integrated

Case and the Parameterization of Scope Ambiguities

This paper argues for a version of Aoun and Li's account of quantifier-scope ambiguities, and for treating the English/Chinese contrast in ambiguity patterns as a difference in how Case is assigned to subjects: under government (Chinese) vs. agreement (English). I argue that the Copy Theory of movement allows the prediction of ambiguity in Someone must have left and Everyone doesn't like squid; English subjects in Spec,IP optionally delete at LF, allowing their VP-internal copies to adjoin below must/n't (giving the subject's narrow scope reading). But subjects with governed Case cannot delete, so the Chinese equivalents are unambiguous. The same distinction underlies the Chinese/English difference for (e.g.) Everyone recommended a book. English subjects, with agreement Case, allow objects to raise over them at LF; but Chinese subjects, with governed Case, block objects from raising, preventing ambiguity. Evidence for this account comes from correct predictions about ambiguity in sentences with double objects or PPs; correlations with ECP phenomena; and the fact that Japanese, Korean, and Persian behave (largely) like Chinese.

Lexical Ambiguity in Poetry

Acknowledgements Introduction Aim and scope Ambiguity in poetry: a critical survey The status of ambiguity in poetry Some definitions of literary ambiguity Organisation of chapters Notes. Towards a re-definition of ambiguity Clarifying some essential terms Meaning, and 'significance' 'Lexical ambiguity' Some useful related notions Type-token distinction Actual and potential ambiguity Context, reader and relevance Notes. A semantic-pragmatic approach to ambiguity Distinctions between semantics and pragmatics A semantic approach to ambiguity Sense relations A pragmatic approach to ambiguity Implicature and the cooperative principle The notion of relevance A Re-definition of ambiguity Notes. The role of context in ambiguity The importance of context in a study of ambiguity Linguistic views on context Literary views on context The Nature of context Coherence and relevance Context and reader Context and ambiguity in the poetic text Context and ambiguit Text and context Conclusion Notes. The role of reader in ambiguity Reader-response criticism The reader and ambiguity Subjectivity and the status of the reader Interaction between reader and text Type-reading and token-reading Conclusion Notes. Ambiguity and cognate phenomena Double or multiple meaning Indeterminacy Vagueness Obscurity Pun Conclusion Notes. Sources of lexical ambiguity Metaphors Other figures Metonymy Symbolism Allegory Paradox Irony Lexical innovation Compounding Derivation Referential uncertainty Conclusion Notes. Conclusion Micro-ambiguity and macro-ambiguity The poetic value of lexical ambiguity Some final remarks. References. Index.

Quantifiers, Anaphora, and Intensionality

The relationship between Lexical-Functional Grammar (LFG) functional structures (f-structures) for sentences and their semantic interpretations can be formalized in linear logic in a way that correctly explains the observed interactions between quantifier scope ambiguity, bound anaphora and intensionality. Our linear-logic formalization of the compositional properties of quantifying expressions in natural language obviates the need for special mechanisms, such as Cooper storage, in representing the scoping possibilities of quantifying expressions. Instead, the semantic contribution of a quantifier is recorded as a linear-logic formula whose use in a proof will establish the scope of the quantifier. Different proofs can lead to different scopes. In each complete proof, the properties of linear logic ensure that quantifiers are properly scoped. The interactions between quantified NPs and intensional verbs such as ’’seek‘‘ are also accounted for in this deductive setting. A single specification in linear logic of the argument requirements of intensional verbs is sufficient to derive the correct reading predictions for intensional-verb clauses both with nonquantified and with quantified direct objects. In particular, both de dicto and de re readings are derived for quantified objects. The effects of type-raising or quantifying-in rules in other frameworks just follow here as linear-logic theorems. While our approach resembles current categorial approaches in important ways (Moortgat, 1988, 1992a; Carpenter, 1993; Morrill, 1994) it differs from them in allowing the greater compositional flexibility of categorial semantics (van Benthem, 1991) while maintaining a precise connection to syntax. As a result, we are able to provide derivations for certain readings of sentences with intensional verbs and complex direct objects whose derivation in purely categorial accounts of the syntax-semantics interface appears to require otherwise unnecessary semantic decompositions of lexical entries.

Model theoretic semantics for Japanese floating quantifiers and their scope properties

A model theoretic and fully compositional treatment of floating quantifiers in Japanese is proposed employing a surface-based syntactic analysis. The present account not only overcomes a difficulty arising from the fact that a floating quantifier and its host are structurally independent of each other but is also capable of offering a principled account for scope ambiguity involving a floating quantifier and other quantificational elements.

Resolution of quantifier scope ambiguities

Various processing principles have been suggested to be governing the resolution of quantifier scope ambiguities in sentences such as Every kid climbed in a tree. This paper investigates structural principles, that is, those which refer to the syntactic or semantic positions of the quantified phrases. To test these principles, the preferred interpretations for three grammatical constructions were determined in a task in which participants made speeded judgments of whether a sentence following a doubly quantified sentence was a reasonable discourse continuation of the quantified sentence. The observed preferences cannot be explained by any single structural principle, but point instead to the interaction of several principles. Contrary to many proposals, there is little or no effect of a principle that assigns scope according to the linear order of the phrases. The interaction of principles suggests that alternative interpretations of the ambiguity may be initially considered in parallel, followed by selection of the single interpretation that best satisfies the principles. These results are discussed in relation to theories of ambiguity resolution at other levels of linguistic representation.

A feature-based syntax/semantics interface

Syntax/semantics interfaces using unification-based or feature-based formalisms are increasingly common in the existing computational linguistics literature. The primary reason for attempting to specify a syntax/semantics interface in feature structures is that it harmonizes so well with the way in which syntax is now normally described; this close harmony means that syntactic and semantic processing (and indeed other processing, see below) can be as tightly coupled as one wishes — indeed, there need not be any fundamental distinction between them at all. In this paper, we first point out several advantages of the unification-based view of the syntax/semantics interface over standard views. These include (i) a more flexible relation to nonsyntactic constraints on semantics, (ii) a characterization of semantic ambiguity, which in turn provides a framework in which to describe disambiguation, and (iii) the opportunity to underspecify meanings in a way difficult to reconcile with other views. The last point is illustrated with an application to the notorious scope ambiguity problem.

A feature-based syntax/semantics interface

Syntax/semantics interfaces using unification-based or feature-based formalisms are increasingly common in the existing computational linguistics literature. The primary reason for attempting to specify a syntax/semantics interface in feature structures is that it harmonizes so well with the way in which syntax is now normally described; this close harmony means that syntactic and semantic processing (and indeed other processing, see below) can be as tightly coupled as one wishes — indeed, there need not be any fundamental distinction between them at all. In this paper, we first point out several advantages of the unification-based view of the syntax/semantics interface over standard views. These include (i) a more flexible relation to nonsyntactic constraints on semantics, (ii) a characterization of semantic ambiguity, which in turn provides a framework in which to describe disambiguation, and (iii) the opportunity to underspecify meanings in a way difficult to reconcile with other views. The last point is illustrated with an application to the notorious scope ambiguity problem.

Dealing with Ambiguities by Underspecification: Construction, Representation and Deduction

In this paper we develop a theory of language meaning that represents scope ambiguities by underspecified structures. The set of possible meanings of a sentence, or text is determined by a set of meta-level constraints that restricts the class of semantic representations appropriately. Thus the way ambiguities are represented does not correspond to any of the usual concepts of formalizing ambiguities by means of disjunctions. A sound and complete proof theory is provided that relates these structures directly, without considering cases.

Transportability, scope ambiguity of adverbials and the Generalized Binding theory

There has been much discussion, mainly by Montague grammarians, of the fact that ‘transportation’ of adverbials affects use or semantic interpretation of perfect sentences. Consider, for example, the following perfect sentences: (1) with a durational PP in sentence-final position; (2) with a durational PP in sentence-initial position; and (3) with a durationalwh-phrase in sentence-initial position:(1) John has been in Tucson for two years.(2) For two years, John has been in Tucson.(3) How long has John been in Tucson?(4) (a) John has been in Tucson for two years up to now.(b) John was in Tucson for two years in the past.

Decompositional composition: The semantics of scope ambiguities and ?bracketing paradoxes?

The assumption that attribute phrases like nuclear physicist constitute a bracketing paradox which may be resolved by special rules such as head rules, rebracketing rules, and productive backformation has gone unchallenged for more than a decade. This paper argues that such structural solutions do not work, since the same scope problems are reflected in phrases based on underived words with no morphological bracketing at all. In their place, a solution based on decompositional or featural composition is proposed, in which attributes compose semantically not with the full set of features of their head, but rather with only one particular feature. This solution reduces the wide and narrow scope readings of attribute phrases to a question of which feature is selected, in effect making all attribute composition the same and obviating the distinction between wide and narrow scope readings of attribute phrases.

Quantified Modal Logic and the Plural De Re

within a language whose only modal operators are the box and the diamond; other modal idioms cannot be expressed within such a language at all. Nonetheless, quantified modal logic has enjoyed considerable success in uncovering and explaining ambiguities in modal sentences and fallacies in modal reasoning. A prime example of this success is the now standard analysis of the distinction between modality de dido and modality de re. The analysis has been applied first and foremost to modal sentences containing definite descriptions. Such sentences are often ambiguous between an interpretation de dicto, according to which a modal property is attributed to a proposition (or, on some views, a sentence), and an interpretation de re, according to which a modal property is attributed to an individual. When these sentences are translated into the language of quantified modal logic, the de dicfo/de re ambiguity turns out to involve an ambiguity of scope. If the definite description is within the scope of the modal operator, then the operator attaches to a complete sentence, and the resulting sentence is de dicto. If the definite description is outside the scope of the modal operator, then the operator attaches to a predicate to form a modal predicate, and the resulting sentence is de re. Quantified modal logic has the resources to clarify and disambiguate English modal sentences containing definite descriptions. In this paper, I explore to what extent the analysis in terms of scope can be applied to modal sentences containing denoting phrases other than definite descriptions, phrases such as ‘some F’ and ‘every F.1 I will focus upon categorical modal sentences of the following two forms: mo s a1 idioms must be artificially restructured if they are to be expressed

Psychofunctionalism and Chauvinism

The psychofunctionalist claim that psychological terms can be defined through the use of an experimental theory has been criticized on the grounds that it is “chauvinistic“: that it denies mentality to any creature of which the selected theory is false. I analyze the “argument from science fiction” that is thought to establish this conclusion, and show that its plausibility rests on a scope ambiguity in formulations of functional definitions. One formulation is indeed chauvinistic, but an alternative rendering is not, and is perfectly consistent with ascribing mentality to creatures of which the selected psychological theory is false. This alternative interpretation of psychofunctionalism is set out in detail, defended from several objections, and finally tied to the semantics of ordinary language psychological terms.

A controlled quantification in parsing of montague grammar

Montague grammar [5] provides good framework for direct translation from natural language sentence into its formulas. This is enabled by the fact that syntactic rule has its corresponding translation rule. As soon as subphrase is recognized by syntactic rule, its corresponding translation rule translates the recognized subphrase into its formula. M-grammar of Landsbergen [3] and semantic equivalence parsing (SEP) of Warren and Friedman [7] are parsing algorithms that are based on the above framework of Montague grammar. In this paper, only version of Montague grammar is discussed, that is, the grammar for the fragments in proper treatment of quantification in ordinary English (PTQ) of Montague [4]. This version is peculiar but most well known. Syntactic rules of Montague grammar consist of context-free rules and noncontext-free rules. The context-free rules scan the given input sentence and recognize its syntactic structure. The noncontext-free rules are the quantification rules whose roles are to treat semantic problems as follows [2]: (1) They bind anaphoric pronouns to their coreferential noun phrases (e.g., a woman walks and she talks). (2) They handle the de re~de dicto (or specific/ nonspecific) ambiguities in opaque contexts (e.g., John seeks unicorn). (3) They handle the scope ambiguities which are caused by more than one quantifier in sentence (e.g., every man loves woman). However, quantification rules can be applied to any phrase which does not need any quantification. At parsing step, it cannot be determined whether quantification rule should be applied or not. This nondeterminism causes wrong applications of quantification rules, or redundant parsing paths. SEP [7] is nondeterministic program such that parsing path is tried. If an application of quantification rule results in wrong parse, SEP backtracks and one of the other alternative rules is tried. On the other hand, if distinct parsing paths translate an input sentence into equivalent formulas, only the first one is printed. Here, the equivalency of formulas is determined by an equivalency test. However, it is an undecidable problem to test the equivalence of intensional formulas [7]. (The intensional logic is the underlying logic of Montague grammar.) Hence, SEP uses the following weaker definition of equivalence: logical formulas are equivalent if they are identical within change of bound variable, after reduction and extensionalization. By this definition only, the equivalence of intensional formulas cannot be completely tested. In this paper, parsing algorithm is proposed,

From English to logic: context-free computation of conventional logical translation

We describe an approach to parsing and logical translation that was inspired by Gazdar's work on context-free grammar for English. Each grammar rule consists of a syntactic part that specifies an acceptable fragment of a parse tree, and a semantic part that specifies how the logical formulas corresponding to the constituents of the fragment are to be combined to yield the formula for the fragment. However, we have sought to reformulate Gazdar's semantic rules so as to obtain more or less 'conventional' logical translations of English sentences, avoiding the interpretation of NPs as property sets and the use of intensional functors other than certain propositional operators. The reformulated semantic rules often turn out to be slightly simpler than Gazdar's. Moreover, by using a semantically ambiguous logical syntax for the preliminary translations, we can account for quantifier and coordinator scope ambiguities in syntactically unambiguous sentences without recourse to multiple semantic rules, and are able to separate the disambiguation process from the operation of the parser-translator. We have implemented simple recursive descent and left-corner parsers to demonstrate the practicality of our approach.