Tamar Vilner

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.

Predictors For success in studying CS

Nathan Rountree Department of Computer Science University of Otago PO Box 56, Dunedin, New Zealand rountree@cs.otago.ac.nz Tamar Vilner Computer Science Department Open University of Israel 16 Klausner Street,Tel Aviv, Israel 61392 tami@cs.openu.ac.il Brenda Cantwell Wilson Dept of Computer Science and Information Systems Murray State University 652 Business Building South Murray, KY, USA 42071-3314 Brenda.Wilson@murraystate.edu Roger Boyle School of Computing University of Leeds Leeds, LS2 9JT, UK roger@comp.leeds.ac.uk

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.

Assessing the assessment — Insights into CS1 exams

The Open University of Israel (OUI) is an institution of higher education which has an open admissions policy and is based primarily on distance learning. The CSI course at the OUI is similar to introductory computing courses at other universities in Israel and worldwide. Over the years, we have composed some tens of CSI final exams and collected data related to the exams. Since there is a high dropout rate for this introductory course, we decided, among other things, to analyze the data examining the different types of questions and the different topics the questions deal with, trying to find out whether the situation can be improved. We examined 3,646 individual exams, collected from 25 final exams administered between 2008 and 2012. The objective was to attempt to identify the difficulties the students faced and to provide us with guidelines for writing final exams in CSI which reflect better the material covered, becoming a fairer assessment instrument and decreasing the failure rate.

Teaching algorithm efficiency in a CS1 course SBTa different approach

Having found that algorithm efficiency is difficult for students to grasp, we advocate a different didactic approach in the introductory CS course (CS1). By exposing students to a number of possible solutions to the same problems, students internalize the concept of a more efficient algorithm.