During the past two decades, numerous studies have compared the effects of independent variables on explicit and implicit measures of memory in both amnesic patients and normal participants (for reviews see Moscovitch et al., 1993; Roediger and McDermott, 1993). The primary goal of these studies was to demonstrate functional dissociations between explicit and implicit measures of memory. Briefly, a functional dissociation is observed if the nature of the effects of experimental (e.g., levels of processing) or participant (e.g., amnesic vs. nonamnesic) variables differs across explicit and implicit tasks. As pointed out by Dunn and Kirsner (1988, 1989, 2003), although many such dissociations have been reported, there is no general consensus as to their interpretation. The present paper attempts to highlight a related methodological concern, namely the issue of task comparability. In contrast to direct or explicit memory tests such as recognition and recall, in which participants are instructed to refer back to the study episode, indirect or implicit tests of memory attempt to disguise the relation between the study and test phases of the experiment by presenting them as unrelated tasks. However, in addition to this instructional manipulation, explicit and implicit tasks employed often differ in terms of several other task dimensions including retrieval cues, metric and susceptibility to response bias (see Reingold and Merikle, 1988, 1990; Reingold and Toth, 1996). Each of these task dimensions will be briefly discussed below: 1) Retrieval cues. The nature of the test cues available during retrieval routinely differs across the explicit and implicit tasks. For instance, if a word (e.g., BLANK) is presented during study, the same word would be presented as a test cue in a recognition task, in a degraded form (e.g., brief presentation followed by a mask), in a perceptual identification task, with only the first three letters in a stem completion task (e.g., BLA ___), with several letters deleted in a fragment completion task (e.g., B __ A __ K ), and not at all in a free recall task. 2) Response Metric. Explicit and implicit indices of memory often employ very different measurement scales. Given this variability in response metric it is difficult to compare the magnitude of the effects of independent variables on explicit versus implicit measures. For example, although it may be clear that a particular experimental manipulation produced 65% correct responses on a forced choice recognition task and a 20-ms. priming effect on a lexical decision task, comparing the relative magnitude of these effects is far from straightforward.