Performance assessments of diagnostic systems under the FROC paradigm: experimental, analytical, and results interpretation issues.

As use of free response receiver-operating characteristic (FROC) curves gains more acceptance for quantitatively assessing the performance of diagnostic systems, it is important that the experimentalist understands the possible role of this approach as one of the experimental design paradigms that are available to him or her among all other approaches as well as some of the issues associated with FROC type studies. In a number of experimental scenarios, the FROC paradigm and associated analytical tools have theoretical and practical advantages over both the binary and the ROC approaches to performance assessments of diagnostic systems, but it also has some limitations related to experimental design, data analyses, clinical relevance, and complexity in the interpretation of the results. These issues are rarely discussed and are the focus of this work.