Book excerpt: The genesis of this volume was the participation of the editors in an ACMlSIGIR (Association for Computing Machinery/Special Interest Group on Information Retrieval) workshop entitled "Beyond Word Relations" (Hetzler, 1997). This workshop examined a number of relationship types with significance for information retrieval beyond the conventional topic-matching relationship. From this shared participation came the idea for an edited volume on relationships, with chapters to be solicited from researchers and practitioners throughout the world. Ultimately, one volume became two volumes. The first volume, Relationships in the Organization of Knowledge (Bean & Green, 200 I), examines the role of relationships in knowledge organization theory and practice, with emphasis given to thesaural relationships and integration across systems, languages, cultures, and disciplines. This second volume examines relationships in a broader array of contexts. The two volumes should be seen as companions, each informing the other. As with the companion volume, we are especially grateful to the authors who willingly accepted challenges of space and time to produce chapters that summarize extensive bodies of research. The value of the volume clearly resides in the quality of the individual chapters. In naming this volume The Semantics of Relationships: An Interdisciplinary Perspective, we wanted to highlight the fact that relationships are not just empty connectives. Relationships constitute important conceptual units and make significant contributions to meaning.