Interpreting the Knowledge Map of Digital Library Research (1990–2010) Son Hoang Nguyen Information & Knowledge Management, University of Technology Sydney, 15 Broadway, Ultimo, NSW 2007, Australia, and Faculty of Information and Library Science, Vietnam National University, 336 NguyenTrai, ThanhXuan, Hanoi, Vietnam. E-mail: n_hoangson@yahoo.com; Hoang.S.Nguyen@student.uts.edu.au Gobinda Chowdhury Information & Knowledge Management, University of Technology Sydney, 15 Broadway, Ultimo, NSW 2007, Australia. E–mail: Gobinda.Chowdhury@uts.edu.au A knowledge map of digital library (DL) research shows the semantic organization of DL research topics and also the evolution of the field. The research reported in this article aims to find the core topics and subtopics of DL research in order to build a knowledge map of the DL domain. The methodology is comprised of a four-step research process, and two knowledge organization methods (classification and thesaurus building) were used. A knowledge map covering 21 core topics and 1,015 subtopics of DL research was created and pro- vides a systematic overview of DL research during the last two decades (1990–2010). We argue that the map can work as a knowledge platform to guide, evaluate, and improve the activities of DL research, education, and practices. Moreover, it can be transformed into a DL ontology for various applications. The research method- ology can be used to map any human knowledge domain; it is a novel and scientific method for producing comprehensive and systematic knowledge maps based on literary warrant. Introduction Research and development activities in digital libraries (DLs) have grown quite significantly in the last two decades, drawing researchers and practitioners from a range of fields, primarily computer science (63%) and library and informa- tion studies (LIS) (26%) (Web of Knowledge, 2011). A search of the Scopus database reveals a dramatic rise in the number of publications (articles, papers, etc.) from 436 during the first decade (1990–1999) to 7,469 during the second decade (2000–2010) (Scopus, 2011). Because of its interdisciplinary nature, the field of DL research involves a large number of topics and subtopics which can be structured in a knowledge map to help educators and researchers in exploring and understanding the DL knowledge domain and its evolution. Nguyen and Chowdhury (2011) reported on research that aimed to build a DL knowledge map, but due to space limitations they could only report briefly on the study’s methods and list some major DL topics and subtopics. This article reports on that research, providing the research background, details of the methodology, and the full DL knowledge map with interpretations. Literature Review Knowledge Mapping Geographically speaking, a knowledge map or a naviga- tion map is a visual representation of an area that provides a symbolic depiction highlighting relationships between ele- ments of that space such as objects, regions, and themes (Njue, 2010). Road maps are regularly used by travellers on land, sailors use their charts when they go to sea, and scientists often rely on spatial knowledge maps when they practice science. Likewise, semantic or word-based knowl- edge maps are often used by students, teachers, and researchers as learning, teaching, knowledge navigation, and assessment tools (Fisher, Wandersee, & Moody 2002). In general, a knowledge map may be considered as a knowl- edge “yellow pages” or a cleverly constructed database pointing to knowledge (Zins, 2007b). It is a guide, not a repository (Davenport & Prusak, 1998). The idea of knowledge mapping in the knowledge man- agement field can be analogous to the use of concept maps and concept mapping. According to Lanzing ( 1997), concept Received April 3, 2012; revised September 7, 2012; accepted September 7, 2012 © 2013 ASIS&T • Published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/asi.22830 JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, ••(••):••–••, 2013