Recursion is a central concept in computer science, yet it is difficult for beginners to comprehend. Israeli high-school students learn recursion in the framework of a special modular program in computer science (Gal-Ezer & Harel, 1999). Some of them are introduced to the concept of recursion in two different paradigms: the procedural…

Constructing a data model for a problem area requires identifying and formulating some symbolic representation of the concepts involved, their characteristics, and the relationships between them. Taking a socio-cultural perspective on learning, analysis of classroom dialog is used to identify cognitive challenges met by novice students of data…