The Intellectual Structure of Knowledge in the Field of the Digital Library:a Co-Word Study

The field of digital library in today's world is diversified and developed and has an interdisciplinary nature. So that the study in its various aspects is always evaluated as one of the important topics in scientific fields and can be the origin of important researches. The purpose of this study is to investigate and plot the intellectual structure of knowledge in the field of digital library in the world using a co-word analysis.

This research is a type of applied scientometric studies that uses co-word analysis and network analysis. The statistical population was all researches in the field of digital library in the web of science database, which is equal to 5655 records in total. Vosviewer, Netdraw, SPSS and Bibexecl software were also used to analyze and plot the network.

The results showed that the keywords digital library, information retrieval and library are the most frequent words and the most pairs of words are digital library and information retrieval. The co-word network includes six clusters called knowledge management and digital library, storage and retrieval of digital resources, interaction between digital and non-digital environments and e-learning, electronic resources and media, virtual screening and medical data analysis. The network density is .24 and the average centrality index is .663. The co-word network of the digital library field showed that the keyword digital library is the most central term and plays the main role of this network. The density of the network is .1290, which is not in a favorable condition. This case shows that the sub-domains within the clusters and inter-cluster connections, or the lack of research orientation to the technical issues of content, software and services as the three main elements of digital libraries and single domain. There is a lack of balance between theoretical and applied interdisciplinary research in this field. These findings are consistent with the research results of others. Of course, the low density of the network also indicates that the subjects of the library field have been researched more in a specialized way and less communication has been established between these fields, which is one of the weaknesses of this field. According to the strategic diagram, knowledge management clusters and digital libraries and digital screening are developed clusters and play a pivotal role. The electronic resources and media cluster, although pivotal, is underdeveloped and immature. Other subject clusters are marginal clusters and are emerging topics that have not been sufficiently researched.  In general, the results of this research showed that most of the researches in the field of digital library of the world have been done in the subjects of information retrieval, university libraries, user studies, internet and copyright. Considering that the network density of the digital library field is low, it is clear that researchers have neglected its interdisciplinary fields and the subjects of this field have little connection with each other. By reviewing the clusters obtained, it is concluded that the clusters of knowledge management, digital library and virtual screening have the central role of researches and most of the researches are carried out in this field and on the other hand, despite the fact that the clusters of storing and retrieving digital resources, human and environment interaction. Digital and electronic learning are one of the main and important topics in the field of digital library, they are emerging, marginal and underdeveloped topics, and researchers should direct most of their research in this direction so that these fields also reach a favorable state. In general, the structure of the intellectual network of the digital library field is fragmented, and in order to create a link between the structure of this network, researches should be removed from being single-domain and theoretical and applied interdisciplinary researches should be conducted.