From going between to working together: Learning from structures and attitudes in South Africa’s transition

In the old South Africa, with its inhabitants divided into two worlds by an ideology-driven white minority, H.W. van der Merwe was one of the first white Afrikaners who took the risk of crossing the boundary which in the culture of his own group was upheld as divinely ordained. On account of the radical change in his socio-political convictions, and his resulting research and teaching, he was appointed as director of an institution aiming at improving intergroup relations through applied research and educational programmes. He also took the lead in founding an association for conflict intervention. His remarkable contribution to the anti-apartheid struggle and the eventual resolving of the white-black conflict was not only a structural one, however, but also an interrelated attitudinal one. His outreaching understanding and his courageous quest for justice and peace enabled him to bring adversaries together, and also to confront the unflinching guardians of apartheid. It behoves us, therefore, to celebrate his example and to emulate it in our current context. We may be grateful for the degree to which transition has already taken shape in the new South Africa, but so much remains to be done to minimise sociocultural distances between sectors of fellow-South Africans. H.W.’s legacy may indeed help us to respect ‘them’ and ‘us’ where appropriate, but also to promote an ‘all of us’ orientation as far as fellow-humanly possible

Book Review: Sudan: The Elusive Quest for Peace

Iyob, Ruth & Khadiagala, Gilbert M. 2006African Journal on Conflict Resolution Vol. 8 (1) 2008: pp. 135-13

Foreword

No Abstrac

Die gebruik van Afrikaans vir die notulering van hofverrigtinge gemeet aan demokratiese standaarde

Hitherto both Afrikaans and English have been serving as languages for the recording of court proceedings in South African courts.Governmental spokespersons as well as the Minister of Justice, however, hinted at the possibility of opting for a monolingual English dispensation. This article analyses the cases for and against a monolingual system. Instead of judging these arguments in terms of individual sections of the Constitution, a different course is followed. Since the Constitution itself purports to be imbedded in democratic values, such values are exceptionally relevant as a  yardstick also for policy regarding language(s) of record in South African courts. The content of democratic values is examined and the arguments pertaining to the matter in question are measured against these values. It is concluded that a monolingual English system for the recording of court proceedings would be incongruent with these democratic values

From Cluster to Cloud to Appliance

We propose a client-side virtual machine (VM) as an alternative to on-campus clusters and off-campus clouds as a development environment for students in introductory courses. In Fall 2011, we deployed the CS50 Appliance, our own such VM, to 600 students on campus and, in Fall 2012, to 700 students on campus and 140,000 students online. We present in this work the results of that two-year experiment. The appliance itself is available as open source for others to adapt or adopt. Not only did the appliance enable us to provide students with simpler tools, among them a graphical editor without any latency, it also enabled us to provide more sophisticated tools too, including a web server and database server. Moreover, the appliance ensured that the course's workload no longer required constant Internet access, particularly of students abroad. And the appliance alleviated load on the course's servers, with execution of students' programs now distributed across students' own CPUs. Without the appliance (or more costly clusters or clouds), we certainly could not have accommodated as many as 140,000 students. But some students' laptops, particularly netbooks, struggled under the appliance's weight. Even though designed to be lean, the appliance, like any VM, still consumes resources, particularly RAM. And unforeseen technical difficulties arose in both years, most, but not all, of which we redressed with mid-semester updates and documentation. Overall we have judged our deployment of an appliance a success, superior to past years' clusters and clouds. And we continue to refine the appliance for Fall 2013.Engineering and Applied Science

Moving CS50 into the Cloud

In Fall 2008, we moved Harvard College’s introductory computer science course, CS50, into the cloud. Rather than continue to rely on our own instructional computing infrastructure on campus, we created a load-balanced cluster of virtual machines (VMs) for our 330 students within Amazon Elastic Compute Cloud (EC2). Our goals were both technical and pedagogical. As computer scientists, we wanted more control over our course’s infrastructure (e.g., root access), so that we ourselves could install software at will and respond to students’ needs at any hour without an IT department between us and our systems. As teachers, we wanted easier access to our students’ work (as via su) as well as the ability to grow and shrink our infrastructure as problem sets’ computational requirements demanded. But we also wanted to integrate into the course’s own syllabus discussion of scalability, virtualization, multi-core processing, and cloud computing itself. What better way to teach topics like those than to have students actually experience them. Although Amazon supported our experiment financially with credits, it was not without costs. Serving as our own system administers cost us time, as did some self-induced late-night technical difficulties. But the upsides proved worth it, as we accomplished our goals. We present in this paper what we did right, what we did wrong, and how we did both so that others can more easily build their own home in the cloud.Engineering and Applied Science

Virtualizing Office Hours in CS 50

In Fall 2007, we introduced “virtual office hours” into Harvard College’s introductory computer science course, CS 50, so that students could meet with teaching fellows (TFs) online to discuss problem sets at any hour from anywhere. Our goals were to lower the bar to interaction among TFs and students and to improve the efficiency and convenience of the same. Rather than rely on email and online forums alone, we experimented with Elluminate, third-party software that not only allowed students and TFs to chat via IM and VOIP, it also enabled the latter to see and even share control of the former’s screens (e.g., code in students’ terminal windows). Students, in turn, were able to troubleshoot bugs with TFs by their (virtual) side. We surveyed our nearly 300 students on their experiences with office hours, both physical and virtual. Although most students responded positively to the idea of virtual office hours, only 55% logged in at least once. However, nearly the same number (62%) attended the physical. We ultimately judged our virtual office hours a net positive, with 14% of students attending the virtual (and 21% the physical) “often.” But our experiment was not without some unexpected results. We found that wait times online sometimes matched or exceeded those in the physical lab, partly the result of the software’s own shortcomings and students’ habits online. Ultimately, the audience for these virtual office hours was entirely self-selecting. Those students who liked the experience online opted in, whereas those who preferred more traditional help opted out.Engineering and Applied Science

CS50 Sandbox: Secure Execution of Untrusted Code

We introduce CS50 Sandbox, an environment for secure execution of untrusted code. Implemented as an asynchronous HTTP server, CS50 Sandbox offers clients the ability to execute programs (both interactive and non-interactive) written in any compiled or interpreted language in a tightly controlled, resource-constrained environment. CS50 Sandbox’s HTTP-based API takes files, command lines, and standard input as inputs and returns standard output and error plus exit codes as outputs. Atop CS50 Sandbox, we have built CS50 Run, a web- based code editor that enables students to write code in a browser in any language, whether compiled or interpreted, that’s executed server-side within a sandboxed environment. And we have built CS50 Check, an autograding framework that supports black- and white-box testing of students’ code, leveraging CS50 Sandbox to run series of checks against students’ programs, no matter the language of implementation. We present in this work the pedagogical motivations for each of these tools, along with the underlying designs thereof. Each is available as open source.Engineering and Applied Science

Die taak en metodes van die musiek-opvoeding aan S.A. Universiteite.

In ’n vorige artikel het ek verskillende aspekte van die Musiekopvoeding in Suid-Afrika oorsigtelik behandel en onder andere verwys na die dringende noodsaaklikheid van ’n sistematiese, gebalanseerde opleiding van ’n nuwe Musiekonderwyserstipe.

Reinventing CS50

Computer Science 50 is Harvard College’s introductory course for majors and non-majors alike, enrollment in which both rose and fell along with the dotcoms. Although enrollment peaked in 1996 at 386 students, it had settled by 2002 in the neighborhood of 100. We set out in 2007 to combat that trend by tackling two problems. We hypothesized that CS50 suffered from two, one of perception and one of design. Although, per end-of-term surveys, the course had never lacked for good teachers or good content, the consensus on campus for years had been to beware this particular course. And the course’s own syllabus may very well have been dated in the eyes of students who had begun to carry regularly modern hardware and software in their backpacks and pockets. Not only did we proceed to revamp every one of CS50’s problem sets, we brought its syllabus more in line with technological trends already familiar to students. And we altered the tone of the course to appeal to those “less comfortable” with computing on campus. But we took care to preserve the course’s rigor and underlying fundamentals, lest we do our own students a disservice. Our new approach appears to be working. Between 2006 and 2007, enrollment in CS50 more than doubled from 132 to 282 (+114%). Between 2007 and 2008, enrollment increased another 17% to 330, though even more striking was that year’s 48% increase in female enrollment. By 2009, enrollment remained strong at 338. We present in this work what we have done and why we have done it.Engineering and Applied Science