Effects on word learning from spacing and category variability

Not all categories are made the same. Some categories have high within-category variability (e.g., “vehicles” can look very different) and some have low within-category variability (e.g., “apples” are pretty similar). Categories can also vary on their between-category variability where some categories are very similar to each other (e.g., “apples” and “oranges”) and some are very different (e.g., “apples” and “vehicles”). Studies have found that categories with high within and between variability are learned best in massed formats, and categories with low within and between variability are learned best in interleaved formats. However, the unique contribution of each of these kinds of variability (i.e., within and between) have not been studied independently. These studies investigate the unique contribution of within- and between-category variability to 3-year-old children’s word learning in interleaved and massed presentations. The results inform existing understanding of interleaving in word learning and how category variability impacts learning