In a previous publication we examined the connections between high-school computer science (CS) and computing higher education. The results were promising -- students who were exposed to computing in high school were more likely to take one of the computing disciplines. However, these correlations were not necessarily causal. Possibly those…

Abstraction is one of the most fundamental ideas in computer science (CS), and as such, according to Bruner, it should be taught spirally, starting as early as possible and revisited at every level of education. However, teaching CS abstraction to novices is a very challenging task, and CS educational research has often demonstrated students'…

In view of the recent developments in many countries, for example, in the USA and in the UK, it appears that computer science education (CSE) in primary or secondary schools (K-12) has reached a significant turning point, shifting its focus from ICT-oriented to rigorous computer science concepts. The goal of this special issue is to offer a…

Aiming to collect various concepts, approaches, and strategies for improving computer science education in K-12 schools, we edited this second special issue of the "ACM TOCE" journal. Our intention was to collect a set of case studies from different countries that would describe all relevant aspects of specific implementations of…

In this article, we discuss the possible connection between the programming language and the paradigm behind it, and programmers' tendency to adopt an external or internal perspective of the system they develop. Based on a qualitative analysis, we found that when working with the visual, interobject language of live sequence charts (LSC),…

The gap between enrollments in higher education computing programs and the high-tech industry's demands is widely reported, and is especially prominent for women. Increasing the availability of computer science education in high school is one of the strategies suggested in order to address this gap. We look at the connection between exposure to…

Scratch is a visual programming environment that is widely used by young people. We investigated if Scratch can be used to teach concepts of computer science (CS). We developed learning materials for middle-school students that were designed according to the constructionist philosophy of Scratch and evaluated them in a few schools during two…

Teaching computer science (CS) in high schools, rather than just programming or even computer literacy, is important as a means of introducing students to the true nature of CS, and enhancing their problem-solving skills. Since teachers are the key to the success of any high school educational initiative, any discussion of high school programs…

Reduction is a problem-solving strategy, relevant to various areas of computer science, and strongly connected to abstraction: a reductive solution necessitates establishing a connection among problems that may seem totally disconnected at first sight, and abstracts the solution to the reduced-to problem by encapsulating it as a black box. The…

Nondeterminism is a fundamental concept in computer science that appears in various contexts such as automata theory, algorithms and concurrent computation. We present a taxonomy of the different ways that nondeterminism can be defined and used; the categories of the taxonomy are domain, nature, implementation, consistency, execution and…

Reversing is the notion of thinking or working in reverse. Computer science textbooks and tutors recognize it primarily in the form of recursion. However, recursion is only one form of reversing. Reversing appears in the computer science curriculum in many other forms, at various intellectual levels, in a variety of fundamental courses. As such,…

Non-determinism is one of the most important, yet abstract, recurring concepts of Computer Science. It plays an important role in Computer Science areas such as formal language theory, computability theory, distributed computing, and operating systems. We conducted a series of studies on the perception of non-determinism. In the current research,…

Nondeterminism is an essential concept in mathematics and one of the important concepts in computer science. It is also among the most abstract ones. Thus, many students find it difficult to cope with. In this article, we describe some didactic considerations, which guided the development of a "Computational Models" course for high school…

Solving problems by reduction is an important issue in mathematics and science education in general (both in high school and in college or university) and particularly in computer science education. Developing reductive thinking patterns is an important goal in any scientific discipline, yet reduction is not an easy subject to cope with. Still,…

This paper discusses the role of reduction in computer science and describes a study on undergraduate students' perception of the concept of reduction. Specifically, based on an analysis of students answers to questions addressing different computer science topics, we present several findings regarding the ways in which undergraduate students…