The conspectus, based on a set number of subject descriptors derived essentially from LC subject classifications, provides a consistent framework within which libraries could report subject intensity. While library collection development has been benefitted by using this conspectus, its effectiveness in this digital era is under controversy. The purpose of this study is to survey the concepts and the various types of conspectus in library collection development and to test the applicability of a revised conspectus model to electronic resource management in libraries. For this, the focus was especially put on investigating the characteristics of electronic resources as considered the collection depth usually identified in collection development policies. Previous research has been also surveyed to consolidate their outcomes in order to design a matrix model of conspectus, which put the characteristics, persistence, and collection level in consideration in oder for the design of the conspectus model.