...our prior experience in scientometrics suggested the development of a hierarchical, three-level classification tree. This would afford flexibility in terms of aggregation and disaggregation. One of our design goals was therefore to classify journals into fields, which would subsequently be grouped into subfields, and these into domains. The domains would distinguish between the social sciences, the health sciences, and so forth. The scientific fields would comprise categories such as chemistry, physics, and biology whereas subfields, or scientific specialities, would comprise items such as anatomy, evolutionary biology, analytical chemistry, and so forth.