Competence in many domains rests on children developing conceptual and procedural knowledge, as well as procedural flexibility. However, research on the developmental relations between these different types of knowledge has yielded unclear results, in part because little attention has been paid to the validity of the measures or to the effects of…

Interactions between conceptual and procedural knowledge influence the development of mathematical competencies. However, after decades of research, these interrelations are still under debate, and empirical results are inconclusive. The authors point out a source of these problems. Different kinds of knowledge and competencies only show up…

Results indicate that identity conservation generally does not precede equivalence conservation; instead the two conservations tend to co-occur. (Authors)

The expectation that an effective conservation training procedure would be one in which the child was confronted with opposing points of view was investigated in an experiment and a replication experiment in which the child's point of view was brought into conflict with those of other children. (Author/RY)

From this study it might be concluded that the development of conservation of quantity cannot be explained by maturation. (Author)

The ability to order objects in a series according to some dimension, such as size, is recognized as an important aspect of a child's ability to understand logical concepts. (Author)

In this study children between the ages of 3 and 6 years were each presented with six number problems in which length and density were varied according to the proposed composition rules. (Authors)

Two studies are reported dealing with the responses of preschool children to adjectives which carry connotations of evaluation, potency, and activity among older children and adults. (Authors)

On the basis of these findings, both the measurement techniques of previous studies and Piaget's analysis of seriation are challenged. (Author)

Children who recognize a compensatory relationship between height-width dimensions are more susceptible to conservation training than children who do not recognize this relationship. (Authors)

Results confirm the hypothesis that identity and equivalence conservation require different mental processes. (Authors/MB)

The results provide evidence of remarkable consistency in both accuracy and manner of performance from first grade through college age levels. (Authors)

To the authors' knowledge, this is the first conclusive demonstration that an observer's spontaneous verbalizations can interfere with vicarious rule learning. (Authors)

One finding is that the children in this study did not reach a level in the development of these concepts expected by Piaget of 9-year-olds. (Authors/CB)