Toward unbiased measurement of conscious and unconscious memory processes within the process dissociation framework

L.L. Jacoby's (1991) process dissociation framework has been welcomed as a tool for differentiating controlled and automatic cognitive processes. Several variants of the original process dissociation measurement model are integrated in this article, and it is shown that the model ignores guessing and, hence, response bias. An extension of the original model is suggested that includes guessing parameters. The original model and the extended model are evaluated empirically. In 3 experiments using a yes-no recognition task, response bias was manipulated in various ways. The original model falsely attributes effects of response biases to either controlled or uncontrolled processes or to both. The extended model, in contrast, results in estimates of the contributions of controlled and uncontrolled memory processes that are relatively unaffected by response biases. The extended model is recommended as a measurement tool.