So sánh phương pháp

	HPSG	Lý thuyết Tối ưu
Lĩnh vực	Ngôn ngữ học	Ngôn ngữ học
Họ	Process / pipeline	Process / pipeline
Năm ra đời	1987	1993
Người khởi xướng	Carl Pollard and Ivan Sag	Alan Prince and Paul Smolensky
Loại	Empirical process pipeline	Empirical process pipeline
Công trình gốc	Pollard, C., & Sag, I. A. (1994). Head-Driven Phrase Structure Grammar. Chicago: University of Chicago Press.	Prince, A., & Smolensky, P. (1993). Optimality Theory: Constraint Interaction in Generative Grammar. Blackwell Publishers.
Tên gọi khác	HPSG Grammar, Constraint-Based Syntax	OT, Constraint-Based Phonology
Liên quan	2	1
Tóm tắt	Head-Driven Phrase Structure Grammar (HPSG) is a constraint-based grammatical framework developed by Carl Pollard and Ivan Sag in 1987. HPSG represents linguistic information (phonological, syntactic, semantic) in typed feature structures and derives well-formed expressions through constraints on these structures. Unlike movement-based theories, HPSG models word order and long-distance dependencies through feature sharing and principles of grammar. It has been extensively applied to modeling diverse language phenomena and remains influential in computational linguistics.	Optimality Theory (OT) is a constraint-based framework for modeling phonology and syntax, developed by Alan Prince and Paul Smolensky in 1993. The core idea is that languages produce the optimal output that best satisfies a ranked hierarchy of universal constraints. Rather than listing rules, OT explains linguistic phenomena as solutions to conflicting pressures—sounds and structures emerge as the least bad compromise among competing demands. This framework has revolutionized phonological theory and is widely applied to morphophonology, segmental and suprasegmental analysis, and cross-linguistic variation.