Appendix A is concerned with the characteristics of the user communities and of the information service centers as important factors in the representation of an information service system. The basic characteristics of both centers and communities include their number, size, geographic distribution, and scope of interest. These characteristics are treated as parameters whose values are supplied by the model user. Appendix B deals with all the necessary information required to run the computer program. It consists of data input requirements and operating instructions. Appendix C presents the test cases in four sections: (1) a listing of the qualitative or descriptive aspects of the input data, (2) a discussion of the quantitative data relating to the test cases and means employed to calculate or estimate the required quantitites, (3) a bibliography of sources used in assembling quantitative data, and (4) a "data assembly guide" which lists the steps required to assemble a complete set of input data such as is used in the present modeling effort. Appendix D consists of a description of the program output and modeling results, followed by a discussion of derivative data and the assemblage of comparative data. The emphasis is on presentation of data rather than on interpretation. (Author/RM)