Browsing by Author "Malan, David"

Now showing items 1-20 of 20

    • Advanced Forensic Format: An Open, Extensible Format for Disk Imaging 

      Garfinkel, Simson; Malan, David; Dubec, Karl-Alexander; Stevens, Christopher; Pham, Cecile (International Federation for Information Processing, 2006)
      This paper describes the Advanced Forensic Format (AFF), which is designed as an alternative to current proprietary disk image formats. AFF offers two significant benefits. First, it is more flexible because it allows ...

    • Computational Thinking and Assignment Resubmission Predict Persistence in a Computer Science MOOC 

      Chen, Chen; Sonnert, Gerhard; Sadler, Philip; Malan, David (Wiley, 2020-02-27)
      Massive open online course (MOOC) studies have shown that precourse skills (such as precomputational thinking) and course engagement measures (such as making multiple submission attempts with assignments when the initial ...

    • CS50 Sandbox: Secure Execution of Untrusted Code 

      Malan, David J. (Association for Computing Machinery, 2013)
      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) ...

    • Engaging Students through Video: Integrating Assessment and Instrumentation 

      MacWilliam, Thomas Matthew; Aquino, Rosario John; Malan, David J. (Association for Computing Machinery, 2013)
      CS50 is Harvard’s introductory course for majors and non-majors alike. For years, we have posted videos of the course’s lectures and sections online for the sake of review and distance education alike. But students’ ...

    • Foreseeing the Endgame: Who Are the Students Who Take the Final Exam at the Beginning of a MOOC? 

      Chen, Chen; Sonnert, Gerhard; Sadler, Philip; Malan, David (Informa UK Limited, 2020-01-06)
      Massive open online courses (MOOCs) show highly irregular participation behaviour among users. In this study, using data from Computer Science 50x of HarvardX, we investigated one extreme, yet common strategy to foresee ...

    • From Cluster to Cloud to Appliance 

      Malan, David J. (Association for Computing Machinery, 2013)
      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, ...

    • Going Over the Cliff: MOOC Dropout Behavior at Chapter Transition 

      Chen, Chen; Sonnert, Gerhard; Sadler, Philip; Sasselov, Dimitar; Fredericks, Colin; Malan, David (Informa UK Limited, 2020-01-02)
      Participants’ engagement in massive online open courses (MOOCs) is highly irregular and self-directed. It is well known in the field of television media that substantial parts of the audience tend to drop out at major ...

    • Grading Qualitatively with Tablet PCs in CS 50 

      Malan, David (2009)
      CS 50 is Harvard College’s introduction to Computer Science for majors and non-majors alike. Each week, our 330 students submit programming assignments comprising hundreds of lines of code that must then be graded. Although ...

    • Implementing Public-Key Infrastructure for Sensor Networks 

      Malan, David; Welsh, Matt; Smith, Michael (Association for Computing Machinery, 2008)
      We present a critical evaluation of the first known implementation of elliptic curve cryptography over F<sub>2p</sub> for sensor networks based on the 8-bit, 7.3828-MHz MICA2 mote. We offer, along the way, a primer for ...

    • Moving CS50 into the Cloud 

      Malan, David J. (2010)
      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 ...

    • An Open-Source, API-Based Framework for Assessing the Correctness of Code in CS50 

      Malan, David; Yu, Brian; Zidane, Kareem; Sharp, Chad; van Assema, Jelle (ACM, 2020-06)
      We present check50, an open-source, extensible tool for assessing the correctness of students’ code that provides a simple, functional framework for writing checks as well as an easy-to-use API that abstracts away common ...

    • Podcasting Computer Science E-1 

      Malan, David (Association of Computing Machinery, 2007)
      In recent months [teachers have] become publishers of content and students subscribers thereof by way of podcasts, feeds of audio, video, and other content that can be downloaded to clients like iTunes and devices like ...

    • A Public-Key Infrastructure for Key Distribution in TinyOS Based on Elliptic Curve Cryptography 

      Malan, David; Welsh, Matt; Smith, Michael (IEEE, 2004)
      We present the first known implementation of elliptic curve cryptography over F2p for sensor networks based on the 8-bit, 7.3828-MHz MICA2 mote. Through instrumentation of UC Berkeley's TinySec module, we argue that, ...

    • Rapid Detection of Botnets through Collaborative Networks of Peers 

      Malan, David (2007)
      Botnets allow adversaries to wage attacks on unprecedented scales at unprecedented rates, motivation for which is no longer just malice but profits instead. The longer botnets go undetected, the higher those profits. I present ...

    • Reinventing CS50 

      Malan, David J. (Association for Computing Machinery, 2010)
      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 ...

    • Scaling Office Hours: Managing Live Q&A in Large Courses 

      MacWilliam, Thomas Matthew; Malan, David J. (2012)
      Computer Science 50 (CS50) is Harvard University’s introductory course for majors and nonmajors alike. So that students have an adequate support structure with which to tackle the course’s weekly programming assignments, ...

    • Scratch for Budding Computer Scientists 

      Malan, David; Leitner, Henry (Association of Computing Machinery, 2007)
      Scratch is a "media-rich programming environment" recently developed by MIT's Media Lab that "lets you create your own animations, games, and interactive art." Although Scratch is intended to "enhance the development of ...

    • Streamlining Grading toward Better Feedback 

      MacWilliam, Thomas Matthew; Malan, David J. (Association for Computing Machinery, 2013)
      CS50 is Harvard University's introductory course aimed at majors and non-majors alike. Each week, students complete programming assignments and have traditionally received feedback from staff in the form of comments on ...

    • Teaching Academic Honesty in CS50 

      Malan, David; Yu, Brian; Lloyd, Douglas (ACM, 2020-03)
      We aspire to teach academic honesty in CS50 at Harvard University not only by addressing academic dishonesty when it occurs but by addressing it before it does. By way of communication, course- and campus-wide awareness ...

    • Virtualizing Office Hours in CS 50 

      Malan, David J. (ACM, 1997)
      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 ...