User-centered Computer Science: High-ceiling and Low-floor Approaches to Programming Languages and Algorithms

The use of traditional introductory approaches to computer science needs to be re-evaluated in light of an increasingly technology-savvy cohort of students. New and powerful environments, such as Scratch from MIT and its descendents, provide an excellent base to develop novel approaches to learning computer programming based on constructionist learning theories. In this paper we describe a constructionist approach to introductory computer science that leverages on these new environments, allowing students to learn computer programming without the cognitive overhead usually associated with learning programming and computation. We then describe new tools we have developed that facilitate the extension of the constructivist approach to learning more complex concepts in computer science, bringing students to a deeper understanding of computer science concepts