Secondary analysis of the International Association for the Evaluation of Educational Achievement findings suggest early school entry results in higher mathematics achievement, but not reading or science achievement, as measured at ages 10 and 13. Possible explanations lie in developmental learning sequences, variations between homes and…

This study showed that Oksapmin children not only spontaneously use the indigenous numerical system of their nontechnical culture but also have created new forms of numerical symbolization and calculation to deal with schooling arithmetic problems. Novel conceptual developments, factors mediating the schools effect, and the influence of prior…

How students restructured their scientific ideas in response to contradictions was studied with 166 male and female students (aged 12 to 14 years) who tested their predictions about water displacement by experiment. Conceptual change varied; all subjects tended to hold onto old ideas, even when presented with conflicting information. (SLD)