The purpose of this article is to elaborate Cottrill et al.'s (1996) conceptual framework of limit, an explanatory model of how students might come to understand the limit concept. Drawing on a retrospective analysis of 2 teaching experiments, we propose 2 theoretical constructs to account for the students' success in formulating and understanding…

An outline of a model that provides a new perspective on the conceptual foundations of mathematics and a new approach for the study of children's acquisition of numerical operations is proposed. Attention is viewed as a pulse-like succession of moments and is supported by recent data from neurophysiology. (MP)

An eight-phase model of processes involved in mathematics problem solving is presented. At each phase, results from factor-analytic studies are used to suggest abilities relevant and prerequisite for successful completion of the phase. Presentation of the model is followed by a discussion of implications for teaching and research. (Author/MK)