On Teaching Abstraction in Computer Science: Secondary-School Teachers' Perceptions vs. Practices

Abstraction is a central and fundamental idea of computer science (CS), which is widely used, for example, for simplifying problems and designing algorithms. Many argue that abstraction skills are the most necessary ones for computer scientists. In line with this, abstraction is acknowledged as an essential aspect of CS curricula. However, the literature indicates that CS teachers may lack knowledge about the importance of abstraction and how to teach it. In this qualitative study we closely examined the abstraction-related teaching approaches of eight high-school CS teachers, considering both their reflections on their teaching approach and their actual classroom practice. Our findings indicate that abstraction may not be sufficiently emphasized in class. We also found gaps between the perception of some teachers regarding their abstraction-related teaching approach and their actual way of teaching abstraction in their classrooms.