Repetitions that are distributed over time benefit long-term retention more than when massed. Recent research has suggested that the advantage of spacing may extend to induction learning--learners were better able to identify the artists of previously unseen paintings when, during training, artists' paintings were spaced (paintings by different artists were interleaved) rather than massed (a given artist's paintings were blocked and presented consecutively). Increasing temporal spacing between paintings while maintaining a presentation sequence that was blocked by artist produced test performance no better than massed presentation (both worse than interleaved presentation) (Experiment 1). Displaying paintings by different artists simultaneously produced test performance as good as interleaved presentation and better than massed presentation (Experiment 2). Our findings argue that spacing benefits perceptual induction learning not because of increased temporal spacing per se but rather because interleaving paintings by different artists enhances discriminative contrast between the artists' styles. Copyright © 2011 John Wiley & Sons, Ltd.