The present study reports the findings of an experiment on the effects of explicit information on the learning of German case markings. Fifty-nine learners of first- and second-year German received computer-based processing instruction on German accusative case marking and word order. These learners were divided into two groups: one received explicit information on the nature and form of case marking in German prior to the treatment, and one group did not. We measured the effects of explicit information by tracking correct responses on the computer as participants made their way through the activities. Analyses revealed that explicit information had an effect: those who received explicit information began to correctly respond to stimulus sentences (i.e., began to correctly indicate who did what to whom) sooner than those who did not. These results contradict previous research and suggest a hidden role for explicit information within processing instruction.