The importance of "size and scale" in nanoscience and engineering has been recognized by both scientists and science educators. A solid understanding of this concept is key to the learning of nanoscience. Students, however, have been reported to have considerable difficulty grasping this concept; yet little is known regarding their state…

A 2x3x2 factorial design was used to study the effects of sex, verbalization of concepts by students, and information supplied by other students" or teachers" or performance in a multiple classification seriation task by fourth grade students. There was a significant interaction of sex and information source. (AL)

Constructed response and multiple choice modes of programed instruction were compared. Both formats enhanced classification performance; the effect was greatest when the criterion test was in the same mode as the instruction. (AL)

Explored the development of hierarchical classification and the age at which this ability appears fully developed. Two measures of hierarchical classification ability were administered to primary, elementary, junior high and high school students. Discusses results which support Piaget's contention that this ability is not developed until late…