The book "Head-driven Phrase Structure Grammar" by Carl Pollard and Ivan A. Sag, published in 1994, is a comprehensive and detailed exploration of the state-of-the-art in category-based syntax, specifically HPSG. The authors provide a wide audience with recent developments in a grammatical framework widely used in syntactically oriented research in natural language processing (NLP). The book covers major syntactic phenomena such as agreement, subcategorization, unbounded dependencies, control, binding theory, and quantification. It compares HPSG to other syntactic frameworks, particularly Principles and Parameters, and discusses its applications in computational linguistics. The companion volume, "German in Head-driven Phrase-Structure Grammar," edited by John Nerbonne, Klaus Netter, and Carl Pollard, focuses on German syntax and presents cutting-edge research. It includes technical and theoretical innovations like function composition and domain union, making it highly recommended for those interested in HPSG or German syntax. The review by Jean-Pierre Koenig highlights the book's strengths, including its detailed analyses and empirical coverage, but also points out some shortcomings. These include a lack of explanation of the formal underpinnings of the theory and an insufficient discussion of lexical rules. Despite these issues, the book is praised for its richness and scholarship, and it is considered essential reading for computational linguists and anyone interested in building NLP systems with a sophisticated syntactic component.The book "Head-driven Phrase Structure Grammar" by Carl Pollard and Ivan A. Sag, published in 1994, is a comprehensive and detailed exploration of the state-of-the-art in category-based syntax, specifically HPSG. The authors provide a wide audience with recent developments in a grammatical framework widely used in syntactically oriented research in natural language processing (NLP). The book covers major syntactic phenomena such as agreement, subcategorization, unbounded dependencies, control, binding theory, and quantification. It compares HPSG to other syntactic frameworks, particularly Principles and Parameters, and discusses its applications in computational linguistics. The companion volume, "German in Head-driven Phrase-Structure Grammar," edited by John Nerbonne, Klaus Netter, and Carl Pollard, focuses on German syntax and presents cutting-edge research. It includes technical and theoretical innovations like function composition and domain union, making it highly recommended for those interested in HPSG or German syntax. The review by Jean-Pierre Koenig highlights the book's strengths, including its detailed analyses and empirical coverage, but also points out some shortcomings. These include a lack of explanation of the formal underpinnings of the theory and an insufficient discussion of lexical rules. Despite these issues, the book is praised for its richness and scholarship, and it is considered essential reading for computational linguists and anyone interested in building NLP systems with a sophisticated syntactic component.