How can conscious and unconscious influences of memory be measured? In this article, a process-dissociation procedure (L. L. Jacoby, 1991) was used to separate automatic (unconscious) and consciously controlled influences within a task. For recall cued with word stems, automatic influences of memory (a) remained invariant across manipulations of attention that substantially reduced conscious recollection and (b) were highly dependent on perceptual similarity from study to test. Comparisons with results obtained through an indirect test show the advantages of the process-dissociation procedure as a means of measuring unconscious influences. The measure of recollection derived from this procedure is superior to measures gained from classic test theory and signal-detection theory. The process-dissociation procedure combines assumptions from these 2 traditional approaches to measuring memory.