Several bodies of research have found different results with regard to presentation timing, categorization, and generalization. Both presenting instances at the same time (simultaneous) and presenting instances apart in time (spacing) have been shown to facilitate generalization. In this study, we resolved these results by examining simultaneous, massed, and spaced presentations in 2-year-old children’s (N = 144) immediate and long-term performance on a novel noun generalization task. Results revealed that, when tested immediately, children in the simultaneous condition outperformed children in all other conditions. However, when tested after 15 minutes, children in the spaced condition outperformed children in all other conditions. Results are discussed in terms of how retrieval dynamics during learning affect abstraction, retention, and generalization across time.

We examined how spatial language affected search behavior in a landmark spatial search task. In Experiment 1, two- to six-year-old children were trained to find a toy in the center of a square array of four identical landmarks. Children heard one of three spatial language cues once during the initial training trial (“here,” “in the middle,” “next to this one”). After search performance reached criterion, children received a probe test trial in which the landmark array was expanded. In Experiment 2, two- to four-year-old children participated in the search task and also completed a language comprehension task. Results revealed that children’s spatial language comprehension scores and spatial language cues heard during training trials were related to children’s performance in the search task.

A large literature has documented that comparison and contrast lead to better performance in a variety of tasks. However, studies of comparison and contrast present contradictory conclusions as to when and how these processes benefit learners. Across four studies, we examined how the specifics of the comparison and contrast task affect performance by systematically manipulating the feature variation and category structure in a category extension task performed by 3‐year‐old and 4‐year‐old children. Studies 1 (n = 48, M = 42.6 months) and 2 (n = 48, M = 42. 4 months) investigated comparison and contrast with high‐density categories. Studies 3A (n = 60, M = 43.47 months), 3B (n = 48, M = 53. 2 months) and 4 (n = 48, M = 53.7 months) investigated comparison and contrast with low‐density categories. Results indicated both category structure and feature variation affect the efficacy of comparison and contrast. Copyright © 2012 John Wiley & Sons, Ltd.