The conditional intervention principle is a formal principle that relates patterns of interventions and outcomes to causal structure. It is a central assumption of experimental design and the causal Bayes net formalism. Two studies suggest that preschoolers can use the conditional intervention principle to distinguish causal chains, common cause…

We conducted four experiments to examine developmental differences in preferences for using color, size, and location information to disambiguate hiding places. Three- and 4-year-olds and adults described how to find a miniature mouse that was hidden in one of two highly similar small objects in a dollhouse. In Experiment 1, the hiding places…

A majority of studies on learning disabilities have focused on elementary grades. Although problems with learning disabilities are life-affecting only a few studies focus on deficits in adults. In this study adults with isolated mathematical disabilities (n = 101) and adults with combined mathematical and reading disabilities (n = 130) solved…

Studies were designed to test the prediction that spatial search strategies in infants may be influenced by locomotor experience. The pattern of findings suggests that infants with efficient modes of locomotion are more likely than others to profit from the experiences generated by locomotion. (RJC)

Sixteen intermediate level hearing-impaired students were examined on perceptions that still water remains invariantly horizontal regardless of container tilt. Similar to findings reported for older hearing-impaired students, Ss made more errors with the straight-sided than with the curve-sided containers. Males performed better than females on…

Investigated the pedagogical quality of physical space by adapting a classroom to create a material "educational field" and testing children's performance on a "go to the front and right of the tower" activity. Found that the educational field made it possible for children to put into relation two spatial reference systems and…

Three studies investigated how experiencing nearby locations together in time influenced memory for location in 7-, 9-, and 11- year-olds and adults. Findings suggested that experiencing nearby locations together in time increased the weight children assigned to categorical information in their later estimates of location. Results were similar…

Three experiments using the familiarization-novelty preference procedure confirmed the hypothesis that three-month-old infants could form categorical representations of spatial relations above and below. The infants, after being shown a familiarization diagram with a dot appearing in multiple locations below a line, showed a preference for a novel…

Compared interstimulus interval (ISI) eye movements of 3-month-olds viewing an alternating picture sequence with those of infants viewing an irregular sequence. Found that all infants exhibited shifts during ISIs. Repetitive saccades declined while alternating and anticipatory saccades increased in alternating sequences. ISI shift frequency did…

Five experiments tested hypothesis that the A-not-B error results from general processes that make goal-directed actions to remembered locations. Findings showed that 2-year-olds' performance on the A trial was accurate. When the object was hidden at Location B, searches after 10-second delay were biased in the direction of Location A. This bias…

It has become increasingly common for theories to rely on a constraint that 1 object cannot be in more than 1 place at the same time. Analysis suggests that a 1 object--1 place--1 time constraint as literally stated is false, that a modified constraint is biased toward the visual modality, that it may not be a correct description of the physical…

Spatial matching--the ability to distribute search effort in accord with the distribution of hidden resources--was studied in 18- to 54-month-old children. The principal development was the appropriate use of win-shift response. (Author/RWB)

Children considered preoperational on multiple classification skills and left-right conceptions were trained to work on classification problems under different conditions, including two variations of children working in pairs, and a situation in which children worked alone. Those in collective conditions progressed more significantly than those in…

Scales for object permanence and spatial relationships were administered to 98 severely and profoundly mentally retarded children (mean age 13 years) on three occasions, 6 months apart. Differences in the difficulty of the items were quite stable, but their order of difficulty differed appreciably from that for nonretarded infants. (Author/SB)