Remember-Know (RK) and source memory tasks were designed to elucidate processes underlying memory retrieval. As part of more complex judgments, both tests produce a measure of old-new recognition, which is typically treated as equivalent to that derived from a standard recognition task. The present study demonstrates, however, that recognition accuracy can be qualitatively changed by a RK or source-retrieval orientation. Visual and auditory presentations of words were varied at encoding and at test. The memory test was either a standard (old-new) recognition test, the RK test, or a source (modality) test. No effect of modality match was found on standard recognition. However, recognition accuracy in the RK and modality tests was greater when study and test modalities matched--a result obtained for both 1-step (e.g., R, K, or new?) and 2-step (e.g., old-new decision followed by RK decision for items judged old) versions of these tests. Thus, the RK and source (modality) memory procedures produced a measure of old-new recognition that was qualitatively different than standard recognition, having a greater sensitivity to perceptual information. (Contains 4 tables, 2 figures, and 4 footnotes.)