This paper presents an extension of the process dissociation procedure with wordstem completion, allowing the measurement of the stochastic relation between conscious and automatic processes. The conditional probabilities of conscious remembering with and without automatic processes can be determined. The determination of these conditional probabilities succeeds due to the extension of the process dissociation procedure by an indirect wordstem completion test, without referring to the usual assumptions of the dissociation paradigm. For the evaluation of this extended process dissociation procedure a multinomial model is presented which allows the distinction between voluntary and involuntary conscious memory. The model is applied to a study by ourselves and to an experiment published by Toth, Reingold, and Jacoby (1994). The results show that the assumptions of stochastic independence or redundancy as well as exclusivity of conscious and automatic processes are often violated. Two conscious processes with different probabilities of occurrence are found; voluntary and involuntary conscious memory processes.