Despite evidence that young children are sensitive to differences in angle measure, older students frequently struggle to grasp this important mathematical concept. When making judgments about the size of angles, children often rely on erroneous dimensions such as the length of the angles' sides. The present study tested the possibility that…

Three hundred and forty-one children (M[subscript age] = 9,0 years) engaged in a series of science tasks in collaborative, same-sex pairs or did not interact. All children who collaborated on the science tasks advanced in basic-level understanding of the relevant task (motion down an incline). However, only boys advanced in their conceptual…

This study evaluated the relative effectiveness of home-based, community-based, and state-run early childhood programs across Cambodia. A total of 880 five-year-olds (55% girls) from 6 rural provinces in Cambodia attending State Preschools, Community Preschools, Home-Based Programs, or no programs were assessed twice using the Cambodian…

This study examined whether 12-month-olds will accept words that differ phonologically and phonetically from their native language as object labels in an associative learning task. Sixty infants were presented with sets of English word-object (N = 30), Japanese word-object (N = 15), or Czech word-object (N = 15) pairings until they habituated.…

This study investigated the relation between teachers' (N = 22) use of sophisticated and complex language in urban middle-school classrooms and their students' (mean age at pretest = 11.51 years; N = 782; 568 language minority and 247 English only) vocabulary knowledge. Using videotaped classroom observations, teachers' speech was transcribed and…

This study examined whether the quality of first graders' (mean age = 7.2 years) numerical magnitude representations is correlated with, predictive of, and causally related to their arithmetic learning. The children's pretest numerical magnitude representations were found to be correlated with their pretest arithmetic knowledge and to be…

This longitudinal intervention assessed children's memory at 2-1/2 years (short-term posttest; N = 115) and their memory and narrative at 3-1/2 years (long-term posttest; N = 100) as a function of maternal training in elaborative reminiscing when children were 1-1/2 to 2-1/2 years. At both posttests, trained mothers were more elaborative in their…

A pre- to post-test design was used to evaluate the effects of rule-based instruction on rule observance, copying performance, and discrimination skill. Three ways of imparting rules (demonstration, verbal description, and combined demonstration-verbal description) were examined, and their usefulness was compared to that of copying without…

Two studies demonstrated dissociation between preschoolers' understanding of pictorial and mental representations. Results showed that false picture tasks were significantly easier than false belief tasks. There was no correlation between performance on the two. Children were trained on false belief, false picture, or number conservation tasks;…