Identifying the types of mathematics content knowledge that are most predictive of students' long-term learning is essential for improving both theories of mathematical development and mathematics education. To identify these types of knowledge, we examined long-term predictors of high school students' knowledge of algebra and overall mathematics…

Two experiments examined development of economic understanding among 5-, 7- and 9-year-olds. Found that most 5-year-olds understood the goal of acquiring desired goods, and most 7- and 9-year-olds also understood the goals of seeking profits, acquiring goods inexpensively, and competing successfully with other sellers. Results suggest that older…

Describes three experiments that examined how children (4- to 11-year-olds) use their knowledge of the attributes of living things to infer whether particular objects are alive. (HOD)

This study examined 6- to 8-year-old Slovenian children's acquisition of matrix completion proficiency and compared microgenetic and age-related changes on the task. Microgenetic analyses indicated that: variability of children's errors increased before they discovered the correct strategy, the correct strategy became dominant shortly after…

This paper presents a framework for conceptualizing the different ways in which instructions in experimental tasks may be misunderstood. Five possible types of misunderstandings are identified and discussed: (1) misunderstanding of a particular term in the instructions; (2) misinterpretation of a task because the instructions are difficult to…

This paper reports two experimental studies of the development of time, speed and distance concepts in children. In Experiment I subjects (12 in each of four age groups: 5-, 8-, 11-year-olds, and adults) were asked to judge which of two electric trains on parallel tracks went faster, for the longer distance, or for more time. Subject's knowledge…

Describes and discusses the rule-assessment approach, a new research strategy for studying developmental sequences in children's acquisition of knowledge. Four experiments were conducted to illustrate the utility of this approach across a variety of concepts and a wide range of ages (three-year-olds to college students). (Author/CM)