The recognition memory receiver operating characteristic (ROC) is typically asymmetric with a characteristic elevation of the left-hand portion. Whereas the unequal variance signal detection model (uvsd) assumes the asymmetry results because old item evidence is noisier than new item evidence, the dual process signal detection model (dpsd) assumes it results because old items convey more useful information than new items. To test these assumptions, the models were fit to old/new recognition data and their evidence parameters were used to predict performance on a novelty, three-alternative forced-choice (N3AFC) recognition task. Critically, under the uvsd model, increased old item variance (sigma) predicts poorer N3AFC performance, whereas under the dpsd model, increased recollection rates (Ro) predict better N3AFC performance. Hence, the asymmetry parameters of the two models make divergent predictions. In two experiments the dpsd model's predictions were supported, whereas the uvsd model yielded unpredicted (from that model's perspective) patterns. Through simulation it was also shown that the dpsd model predicted the uvsd model's mispredictions, which resulted because increases in old item noise markedly depress the upper portion of the ROC. Overall, the data demonstrate that increasing ROC asymmetry is not a function of increasingly noisier target evidence, but instead increasingly informative target evidence. These findings invalidate the uvsd model, which heretofore has been primarily supported by its post-hoc fitting ability, not its construct validity.