The acceptance of natural language generation systems strongly depends on their capability to facilitate the exchange of information with human users. Current generation systems consider the influence of situational factors on the content and the form of the resulting utterances. However, the need to time their processing flexibly is usually neglected although temporal factors play a central part when directly addressing a human communication partner. A short response time of a system is crucial for its effective use. Furthermore, some applications --- e.g., the simultaneous description of ongoing events --- even necessitate the interleaving of input consumption and output production, i.e. the use of an incremental processing mode. We claim that incremental processing is a central design principle for developing flexible and efficient generators for speech output. We discuss the advantages of parallel processing for incremental generation and several aspects of control of the generator...

this paper is that neither has been implemented." ([Vaughan and McDonald, 1986], page 95). Although Meteer [1990] gives a detail description of the relationship between text structure and revision it is unclear how the proposed model could contribute to the choice problem of paraphrases (see section 5.2). How- ever, from the approach described above and from the system described in [Meteer, 1990] we can draw the following conclusions. Only the generatoFs input is marked. If the generator encounters alternative realizations the revision component is asked to make the decision. However, to be able to do this it needs detailed knowledge about the grammar. Therefore grammatical knowledge has to be duplicated. The linguistic realization component used in [Meteer, 1990] is MUMBLE-86 [McDonald, 1986]. The text structural representation level must completely specify the infor- mation to be expressed by the utterance. The mapping has to ensure that all the necessary linguistic information is present. Mumblers procedural grammar is used only for generation purposes. Therefore it is without reach for the revision model to take into account relevant sources of ambiguities

We present an active chart parser which parses left connected wordgraphs in a strictly time synchronous way. The parser performs a beam search on the possible paths through the word graph and on the possible derivations of the unification grammar simultaneously. A metric is given to assign scores to edges, taking into account the whole left context thereby combining acoustic probabilities, n-gram probabilities and unification grammar probabilities. A specialized model for the derivation of typed unification grammars is introduced. Different ways of coupling the parser with an LR beam decoder in an online time synchronous fashion are defined and several experimental results are presented. Two top down and one bottom up method are investigated. In bottom up mode, the decoder sends word hypotheses as they are found from left to right, while the parser keeps step. In verify mode, the decoder is always a frame ahead, while the parser verifies received hypotheses, providing language informat...

We describe four different parsing algorithms for Linear Context-Free Rewriting Systems (Vijay-Shanker et al., 1987). The algorithms are described as deduction systems, and possible optimizations are discussed. The only parsing algorithms presented for linear contextfree rewriting systems (LCFRS; Vijay-Shanker et al., 1987) and the equivalent formalism multiple context-free grammar (MCFG; Seki et al., 1991) are extensions of the CKY algorithm (Younger, 1967), more designed for their theoretical interest, and not for practical purposes. The reason for this could be that there are not many implementations of these grammar formalisms. However, since a very important subclass of the Grammatical Framework (Ranta, 2004) is equivalent to LCFRS/MCFG (Ljunglöf, 2004a; Ljunglöf, 2004b), there is a need for practical parsing algorithms. In this paper we describe four different parsing algorithms for Linear Context-Free Rewriting Systems. The algorithms are described as deduction systems, and possible optimizations are discussed. 1 Introductory definitions A record is a structure Γ = {r1 = a1;...; rn = an}, where all ri are distinct. That this can be seen as a set of feature-value pairs. This means that we can define a simple version of record unification Γ1 ⊔ Γ2 as the union Γ1∪Γ2, provided that there is no r such that Γ1.r ̸ = Γ2.r. We sometimes denote a sequence X1,..., Xn by the more compact ⃗ X. To update the ith record in a list of records, we write ⃗Γ[i: = Γ]. To substitute a variable Bk for a record Γk in any data structure Γ, we write

: This thesis describes the work of providing separate morphological processing and part-of-speech tagging modules in the svensk system by integrating the Uppsala Chart Processor (UCP) and a Brill tagger into the system. svensk employs GATE (General Architecture for Text Engineering) as the platform in which the components are to be integrated. Two preprocessing modules, a tokeniser and a sentence splitter for Swedish, were developed in order to facilitate the preparation of the texts to be analysed by UCP and the Brill tagger. These four components were then integrated in GATE together with a newly developed viewer for displaying the results produced by UCP. The thesis introduces the reader to the svensk project, the GATE system and its underlying parts, especially the database architecture which is based on the TIPSTER annotation model. Further, the issues in connection with the development and design of the tokeniser and the sentence splitter for Swedish are elaborated on. The mecha...

Ideally, the time that an incremental algorithm uses to process a change should be a function of the size of "the set of things changed" rather than the size of the entire current input. Building upon a previous notion of change, this paper investigates how and to what extent it is possible to give such a guarantee for a chart-based parsing framework. Two results are provided: first, it is shown that a previously proposed algorithm is unbounded incremental; secondly, it is outlined how a polynomial time bound can be obtained by refining this algorithm.

This work explores the problem of incremental analysis in the context of chart parsing, probably the most commonly used framework for the analysis of natural language. Incrementality here means that syntax correctness of a text is checked dynamically as the text is edited, changing the internal representation of the analysis rather than generating an entirely new one. This implies that the system then may interact with the user in order to resolve problems that occur. As a consequence, these kinds of techniques can be used to develop highly interactive and reactive natural language processors. The kernel of the work is an incremental parsing algorithm that analyses arbitrary changes of a text, allowing competing analyses to be developed in parallel.