a new look at the role of disciplines in citation analysis

the increasing number of scientific journals, even in a subfield, necessitates a reliable and authoritative measure for researchers and libraries to identify core journals in a given subfield. the impact factor value is affected by different factors such as subject area, type of documents or length of the citation measurement window. in order to prioritize the choice of quality journals for scientists and libraries two new measures (indices) have been developed. the dsi is an aid to decision-making with regards to the level of journal specialism within a particular discipline and serves to inform researchers in the field who wish to make individual subscription decisions. dpi has been proposed as a decision-making tool for libraries as it indicates the proportion of all citations within a particular discipline that have been received by a particular journal.