Secondary reinforcing effects interpreted as information processes. The hypothesis that a secondary reinforcing stimulus must have acquired discriminative stimulus properties implies that it also conveys information about the forthcoming appearance of the primary reinforcer, inasmuch as a discriminative stimulus gains control over a response through the correlations: discriminative stimulus-response-reinforcement: other stimulus set-response-nonreinforcement. Egger and Miller (1962) gave this supposition a more precise statement, namely, "a necessary condition for establishing any stimulus as a secondary reinforcer is that the stimulus provide information about the occurrence of primary reinforcement" and, if a situation includes more than one stimulus predicting primary