Towards a Discourse-Oriented Representation of Information Structure in HPSG

A representation for information structure in HPSG was proposed by Engdahl & Vallduv́ı (1996). Arguing that information structure is a distinct dimension, which should not be associated only with phonology, only with syntax, or only with semantics, they propose that a feature INFO-STRUCT (which includes FOCUS and GROUND, the latter including LINK and TAIL) should be located within the CONTEXT feature in the HPSG framework. However, the specific representation which they use is syntactic: LINK and FOCUS are equated with the syntactic constituents (NPs and VPs) which realize the topic concept and the focus information. As the primary concern of Engdahl & Vallduv́ı (1996) is with information packaging, this has the advantage of facilitating the description of the realization of information structure (by intonation in English, by word order in Catalan), but it has the major disadvantage that the packaging is only indirectly tied to the information which is packaged, which is itself part of the semantic content.1 This syntax-based representation of information structure enables the distinction between narrow focus and wide focus to be represented. Example (1) can be interpreted either with narrow focus on the object noun phrase or with wide focus on the whole verb phrase.