Ela Zur

The efficiency of algorithms: misconceptions

The implementation of a new computer science (CS) curriculum in high schools which includes all the basic elements of traditional CS programs, motivated a research to determine how students conceive the very fundamental notion of efficiency. Since this was the first time that algorithm efficiency was integrated into a high school curriculum, our study was crucial for further implementation of the program. This paper describes a study that revealed misconceptions in perceiving the efficiency of algorithms by high school students. We discuss the results, provide some indication of the roots of these misconceptions, suggest ways to prevent them, and recommend further research.

Computer science issues in high school: gender and more....

Computer Science (CS) seems to be one of the few remaining disciplines almost entirely dominated by men, especially among university faculty and in the hi-tech industry. This phenomenon is prevalent throughout the western world. In Israel, we observed it in high schools where only 30% of the students who choose to major in CS are women. It continues in Israeli universities and colleges, where usually less than 30% of CS students are women. In this paper, we provide data describing the situation in Israeli high schools. In addition, we present a survey conducted among high school students which aimed, among other goals, to discover why girls did not choose to take CS in high school. We analyze the data and provide some conclusions and ways to deal with this situation.

Teaching Algorithm Efficiency at CS1 Level: A Different Approach

Realizing the importance of teaching efficiency at early stages of the program of study in computer science (CS) on one hand, and the difficulties encountered when introducing this concept on the other, we advocate a different didactic approach in the introductory CS course (CS1). This paper describes the approach as it is used at the Open University of Israel (OUI). The OUI, a distance teaching institution with no prior educational requirements, runs a full-fledged CS program. Because of its open door policy, the dropout rate, especially in introductory courses, as well as the percentage of failures, is very high. Using the new approach has raised the percentage of students who pass the course. The new approach advocates integrating three-part questions which ask not only to identify the algorithmic problem that a given algorithm solves and to analyze its complexity, but also to design a new algorithm that performs the same task, while increasing efficiency by an order of magnitude, not only by a constant factor. The research we conducted to examine the implications of using this approach is described here.

Has the paradigm shift in CS1 a harmful effect on data structures courses: a case study

The ongoing debate among Computer Science educators about the advantages and disadvantages of the shift from the procedural to the Object-Oriented paradigm usually relates to the introductory course. Indeed, we were also concerned when in our institute we decided to implement this shift in our introductory course and started to teach Java, instead of a procedural paradigm. In our previous study we saw that the effect of the shift did not lower the achievements of students taking the CS1 course. Furthermore, we wanted to be equally sure that this was the case when students take Data Structures courses. This is the focus of the study presented in this paper. The results show that there is no significant difference in the achievements of students who came from different paradigm backgrounds. This encouraging result probably relates to the fact that our CS1 course focuses on the fundamentals of introductory Computer Science and does not only emphasize the language aspects.

Once She Makes It, She's There!: A Case Study.

Computer science is possibly one of the few remaining disciplines almost entirely dominated by men, especially university staff and in the hi-tech industries. This phenomenon prevails throughout the western world; in Israel it starts in high school, where only 30% of students who choose to take computer science as an elective are women, and continues in university and college, where usually less than 30% of the entire computer science student population is female. In this paper we present data describing women taking the undergraduate computer science program at the Open University of Israel. Covering a period of 10 years, we have examined the enrollment and results of thousands of students on 20 undergraduate computer science courses. An attempt has been made to identify whether there is a specific stage in the undergraduate program which is more difficult for women to pass. The good news is that within the Open University of Israel out of the entire population of computer science students the percentage of female enrolments and the percentage of females graduating is almost the same, and the differences in average final grade between men and women are generally not significant. This study is unique because of the large number of students which served as the study population, covering the entire undergraduate program.

Software Design Course for Leading CS In-Service Teachers

The Computer Science (CS) discipline is continually developing. Consequently there are frequent changes in curricula and their implementations. The CS teachers, who usually work in schools alone or in small teams, are seriously challenged by the changes, since all their teaching materials and pedagogical methods have to be revised. In Israel, the secondary school CS program has recently shifted from the procedural to the OOP paradigm. This paper discusses an approach taken to address the ensuing difficulties, namely a course for leading teachers. The paper describes the rationale of leading teachers, and a course conducted for them in an advanced unit in the CS program. The main purpose of the course was to develop a professional leadership of CS teachers who can support and contribute to their peers. The paper describes the expectations of the course; its progress; and the conclusions about its success obtained by analyzing data collected during the course.

Advanced programming in java workshop: teaching methodology

This paper describes the Advanced Programming in Java Workshop given in the Computer Science (CS) department of the Open University of Israel (OUI). The workshop is based primarily on J2EE technologies. We will describe the methodology of the workshop which combines several academic skills which we believe every university graduate must be exposed to.

Using greenfoot in teaching inheritance in CS1

In the Open University of Israel CS1 course, there are eight assignments contributing various percentages to the overall course assessment. The concepts of inheritance and polymorphism are covered in assignment 5. In the fall semester of 2009, assignment 5 was changed to demonstrate these topics using the Greenfoot environment. Here we describe this assignment and its rationale.

Individual and group seminars and workshops in the computer science curriculum

The Open University of Israel (OUI) is an institution of higher learning which has an open admission policy and is based primarily on distance learning. The OUI offers several Computer Science programs. In order to complete the requirements in each of the undergraduate CS programs, the students are required to take at least one workshop or seminar. The aim of the seminar/workshop is to introduce students to advanced CS theoretical or practical topics. Students investigate an advanced topic, prepare and submit a final paper or project, and present their study in a lecture to faculty members and students. We detected a problem that a relatively large number of students fail to complete the seminar/workshop requirement. In an attempt to deal with this problem, we conducted a study in order to better understand the reasons for this failure. In the paper we present some statistics regarding the completion of the seminars/workshop requirement, the correlation between this completion and other factors, such as: the number of credits earned by the student and the average grade achieved by the student before enrolling in the seminar/workshop.

Computer science teacher training

The Open University of Israel offers a program of study for Computer Science graduates towards a high school Teaching Certificate in Computer Science. The program is unique in that it enables studying towards the certificate in a distance learning environment and therefore can be pursued by people who wish to combine further education with careers and personal responsibilities. In this paper we describe the Teaching Certificate Program which provides an opportunity for Computer Science graduates to pursue an educational career. Particularly we describe the course “Methodology of Computer Science Teaching” which utilizes multi-media technologies expressly developed for distance learning. In addition we present some statistics regarding the program, such as: the number of students enrolled in the program, age and gender distribution.