The effectiveness of blocked versus interleaved arrangements of to-be-learned categorical material depends on how easily the categories can be distinguished. Interleaving typically enhances learning when categories are difficult to discriminate and helps learners detect subtle differences, whereas blocking is more effective when the categories are easily distinguishable. Our research examines whether these effects extend to naturalistic materials, such as painters’ artistic styles. Participants learned to identify the styles of 12 painters. During learning, they saw six paintings per artist, accompanied by the artist’s name. Half of the artists had highly distinctive styles, while the other half had styles that were difficult to differentiate.

In Experiment 1, participants were assigned to one of two groups. In the blocked condition, all paintings by a given artist appeared consecutively before moving to the next artist. In the interleaved condition, paintings by different artists were mixed. Participants in both groups studied both distinctive and non-distinctive painters. In Experiment 2, the arrangement of paintings (blocked versus interleaved) was manipulated within subjects, while the distinctiveness of the material was manipulated between subjects. During testing, participants viewed new paintings by studied artists as well as paintings by previously unseen artists. They judged whether each painting came from a learned artist and, if so, identified the painter from a list.

Surprisingly, results from Experiment 1 showed that interleaving improved recognition of paintings by distinctive artists compared to blocking. No differences were observed for non-distinctive artists. Data collection for Experiment 2 is ongoing.