Examining Keywords Similarities amongst Scientific Literature of the Electronic, Digital, and Virtual Libraries in Web of Science: Clustering Anal-ysis

This study aims to investigate the keywords similarities of documents in three areas of electronic, digital, and virtual libraries based on cluster analysis.

This scientometric study is conducted using co-word analysis and clustering techniques. Research materials consist of all relevant documents related to electronic, digital, and virtual libraries that have been indexed in Web of Science, during the period 1990-2018. In addition to the superficial similarity observed, the rate of similarities is calculated by the Jaccard index.

An examination of the growth trends indicates a negative and slight increase in the number of documents related to electronic and virtual libraries (with growth coefficients of -0.68 and 36.1). However, the number of digital libraries is higher (-0.68, 1.36, and 13.11 respectively). The topics of "Electronic Resources", "Information Retrieval", and "Internet "are placed at the top of core keywords in the fields of electronic, digital, and virtual libraries, respectively. The clustering of keywords in the three areas of the research led to the formation of 8, 14, and 7 clusters.

Results indicate little overlap of keywords in the three areas in terms of clustering. It reveals an obvious distinction between these three phenomena within the scientific community and can be viewed as evidence of the researchers' proper understanding of the concepts associated with different types of libraries.