This study will experiment with the use of citations among journals to describe disciplinary shifts among the sciences. Factor analysis will be used to measure the structure of science at various heirarchical levels such as disciplines, subfields and specialties, as well as changes in the structure over time -- including changes in interdisciplinarity as well as the emergence of new areas of science. A reliable methodology for tracking the changes in relationships among disciplines and the emergence of new areas of research would be of great value to Science & Engineering Indicators and to its policy oriented audience. The objective of this project is to explore the practical problems in applying the proposed method and the usefulness of its results. The creation of methods for depicting the dynamic structure of science may improve our capacity to more accurately reflect real levels of national participation by field of science than do the current fixed journal sets.
