  Can change in citation patterns among journals be used as an indicator of
structural change in the organization of the sciences? Aggregated
journal-journal citations for 1999 are compared with similar data in the
Journal Citation Reports 1998 of the Science Citation Index. In addition to
indicating local change, probabilistic entropy measures enable us to analyze
changes in distributions at different levels of aggregation. The results of
various statistics are discussed and compared by elaborating the
journal-journal mappings. The relevance of this indicator for science and
technology policies is further specified.
