These experiments explored the role of prior experience in 12- to 18-month-old infants' tool-directed actions. In Experiment 1, infants' use of a familiar tool (spoon) to accomplish a novel task (turning on lights inside a box) was examined. Infants tended to grasp the spoon by its handle even when doing so made solving the task impossible (the…

Examined the relationship between 6- to 8-year olds' conceptual understanding of additive composition, commutativity, and associativity principles and addition problem-solving procedures. Results revealed that conceptual understanding was related to using order-indifferent, decomposition, and retrieval strategies and speed and accuracy in solving…

Three experiments tested 21- and 27-month olds' ability to construct a path to a mentally re-presented goal. After seeing the goal-state configuration of problems, both age groups evinced planning. Demonstration of initial solution step was less effective than goal-state exposure. Even with specification of a greater proportion of the goal path,…

Three experiments examined the role of representations in adolescents' deductive reasoning. Findings indicated that, with age, conditional reasoning improved on tasks containing permission conditional relations; reasoning fallacies increased on tasks containing causal conditional relations. Valid conditional inferences were more common on problems…

Examined patterns of conceptual and procedural knowledge of addition in 5- to 8-year-olds. Found that children were more successful in noticing that addends had been reordered rather than decomposed and in noticing the decomposition of addends presented with objects rather than with symbols. Also found that profiles of procedural competence were…

Examines a model for children's strategies for inclusion tasks. Suggests that young children are not consistent in task strategies and that they display mixed response strategies. Strategies may change with development. (ET)

Three experiments explored the development of formal logical reasoning between Grades 4 and 12 and the role of semantic content in the solution of Wason's (1966) selection task problems. Results suggest that formal logical reasoning is not generally present during the fourth or sixth grades and that formal logical competence becomes available in…

Two experiments examined problem solving in 16-month-olds' adaptive locomotion (crossing bridges of varying width with/without handrail). Findings indicated that toddlers attempted wide bridges more than narrow ones. Attempts on narrow bridges depended on handrail presence. Toddlers had longer latencies, examined bridge/handrail more closely, and…

Eighty-nine children between four and nine years of age solved mazes varying in the presumed appropriateness of advance or improvisational planning. Results of the study show that children's planning strategies are adapted to circumstances and suggest that older children may be more proficient in this adaptation than are younger children. (RH)

Examined whether indexes of verbal imprecision could be quantified and used to predict changes in fifth graders' problem-solving performance. Found that four types of verbal imprecision predicted improved performance: false starts and self-repairs, deletions, long pauses, and metacognitive comments. Results suggested that adopting a new approach…

Compared adolescents' (14 to 20 years) and young adults' (21 to 37 years) wisdom-related knowledge and judgment related to difficult and ill-defined life dilemmas. Rated responses along five wisdom criteria. Found that adolescents performed at lower levels than young adults but also demonstrated substantial age increments in performance.…