"The Western Oil Shales could play a major role in the U.S energy future, providing economic recovery techniques are developed. The Laramie Energy Technology Center (LETC) has the lead responsibility within DOE to assist the commercialization of oil shale. LETC directs R&D programs to identify promising oil shale recovery technologies and to reduce the uncertainties in oil shale recovery, leading to commercial development by industry. The Energy Systems Development Operation (ESDO) of Science Applications, Inc. (SAl) has provided support to LETC in the evaluation of an accelerated oil shale technology program which considered aboveground oil shale retorting and vertical modified in situ (VMIS) oil shale development (Reference 1 included as Appendix A) . The purpose of this study is to apply the SAl commercialization methodology to several other oil shale recovery concepts under investigation by LETC for application to marginal oil shale areas. The basic characteristics of each of the following concepts is sketched in Figure 1: Horizontal(Modified In Situ) (HMIS) Big Hole(Modified In Situ) Springing and Flushing(Modified In Situ) Hydrofracture(True In Situ) Geokinetics(Modified In Situ) Equity(Modified In Situ) Specifically the objectives of this study are: (1) to conduct & comparative engineering/economic analysis of the advanced oil shale concepts to identify which ones have the greatest potential for successful commercialization; (ii) to identify key technical features to be addressed in R&D programs for potentially viable concepts; (iii) to conduct sensitivity studies of potentially viable concepts to assess technical and institutional uncertainties."