Defines five levels between concrete and formal operation in the development of the concept of controlling variables. The sample, methodology and research on which the work is based is described in SE 519 500. (CP)

This study tested certain implied predictions regarding conceptual learning at each of four sequential levels of development: concrete level, identity level, classificatory level, and formal level. For this purpose, scaled batteries to assess the level of conceptual development of children, kindergarten through high school, were constructed and a…

Lesson structure (organization in terms of meaningful relationships among ideas or concepts) is a low-inference indicator of lesson organization in that it can be observed and objectively quantified. It affects achievement positively, and students generally rate lessons higher when the structure of the lesson is relatively high. Teachers vary in…