This report describes a real-time simulation experiment to evaluate the performance of the search and editing system 3RIP, an interactive system written in the language BLISS on a DEC-10 computer. The test vehicle, preliminary test runs, and capacity test are detailed, and the following conclusions are reported: (1) 3RIP performs well up to the capacity limit of the DEC-10, (2) long response times could be reduced by solving the problems of how 3RIP files are distributed and how the scheduling algorithm of the operating systems can be altered in order to give jobs creating I/O accesses a low priority, (3) the test vehicle can be a useful tool to find a suitable system design, and (4) the test vehicle can be used to predict system performance under certain circumstances. Appendices include profiles used for the test, a short description of the contents of the databases INSPEC and COMPENDEX, items of CLIST governing the text, and an example of a test run. (FM)