Conflicting findings with respect to the effects of experimental manipulations on priming have been reported in previous studies. It is argued that, in many priming tasks, large amounts of task-relevant information are available from various sources, and that, therefore, the information available from a specific study episode will have only a small impact on overall performance level. Under such circumstances, high levels of baseline performance and small priming effects will be observed. The experiments reported here investigated the hypothesis that a high baseline performance in informationprocessing tasks that are used to measure priming may constrain priming effects. In a series of wordnaming experiments, perceptual difficulty and, therefore, baseline performance was manipulated. Under easy conditions, priming effects were relatively small and were not affected by word frequency, spaced repetition, or delay.Under more difficult conditions, priming effects were larger, and significant effects of all of the above-mentioned experimental manipulations were observed. Under conditions that produced the largest priming effects, a significantrelationship between printingand explicit-memory performance could be observed. Inthe last experiment, it was shown that the characteristics of the retrieval task can substantially affect the magnitude of priming. It is argued that priming effects should be considered to reflect interactions between memory traces and the information-processing components of the priming task.Experimental manipulations that significantly affect explicit-memory performance on tasks such as recall or recognition often have little or no significant effect on priming measures that are obtained in tasks such as tachistoscopic identification, lexical decision, and word-stem completion. These variables include massed repetition of studied items, divided versus focused attention, and levels ofprocessing ofthe study items