The intent of this method is to delineate one means of comparing cleaved optical fiber end faces with an ideal surface that is smooth, flat and perpendicular to the fiber axis. Comparative measurements of cleaved fiber end faces are useful in the qualitative analysis of cleaving tool performance but are not intended for assessing the potential suitability of a cleaved surface; the intent of this method shall not be confused with the intent of FOTP-57 (EIA-455-57), "Optical Fiber End Preparation and Examination", which is more concerned with the absolute results on particular fiber end(s) than with a comparison of relative results. The device used for this method of comparison is an incident-light interference device (Interferometer).