An investigation is described of the ORT ONLY MODEL, which is one of four models being used to obtain national norm-referenced and local criterion- or objective-referenced information from a single assessment instrument. Raw scores on a norm-referenced test (NRT) were equated to raw scores on an objective-referenced test (ORT). Resultant equating tables were used to estimate norm-referenced scores for examinees taking only the ORT. Preliminary analyses indicated that corresponding ORT and NRT subject tests were similar in terms of content and statistical properties and that correlation coefficients exceeded the minimum levels for ORT-NRT equating set by Chapter I guidelines. Technical considerations, however, indicate that estimated comparable national percentile ranks should be used cautiously. (SLD)