Some of the most common methods of interpreting powder compaction data are described. These include compaction energy versus tablet hardness profiles, Heckel plots, stress relaxation and elastic recovery measurements and radial versus axial pressure cycles. By comparing and critically evaluating the techniques employed and results obtained by independent studies, it is shown that considerable confusion exists in the literature. As well, it is demonstrated that in numerous studies, further substantiation of the techniques employed is required. As a guide for future research, some of the most useful and possibly least ambiguous methods of interpreting compaction data are recommended.