Customizable and scalable automated assessment of C/C++ programming assignments

The correction of exercises in programming courses is a laborious task that has traditionally been performed in a manual way. This situation, in turn, delays the access by students to feedback that can contribute significantly to their training as future professionals. Over the years, several approaches have been proposed to automate the assessment of students' programs. Static analysis is a known technique that can partially simulate the process of manual code review performed by lecturers. As such, it is a plausible option to assess whether students' solutions meet the requirements imposed on the assignments. However, implementing a personalized analysis beyond the rules included in existing tools may be a complex task for the lecturer without a mechanism that guides the work. In this paper, we present a method to provide automated and specific feedback to immediately inform students about their mistakes in programming courses. To that end, we developed the CAC++ library, which enables constructing tailored static analysis programs for C/C++ practices. The library allows for great flexibility and personalization of verifications to adjust them to each particular task, overcoming the limitations of most of the existing assessment tools. Our approach to providing specific feedback has been evaluated for a period of three academic years in a course related to object-oriented programming. The library allowed lecturers to reduce the size of the static analysis programs developed for this course. During this period, the academic results improved and undergraduates positively valued the aid offered when undertaking the implementation of assignments.Universidad de Cádiz, Grant/Award Numbers: sol-201500054192-tra, sol-201600064680-tra; Ministerio de Ciencia, Innovación y Universidades, Grant/Award Number: RTI2018-093608-B-C33; European Regional Development Fun

Tools and Environments

Teaching and learning how to build software are central aspects of computing education, and the tools which we use to support this are themselves a focus of research and innovation. This chapter considers tools designed or predominately used for education; from software development environments to automatic assessment tools, visualization, and educational games platforms. It looks at not just the history and state-of-the-art of these tools, but also at the challenges and opportunities in researching with and about them

Functional Programming For All! Scaling a MOOC for Students and Professionals Alike

Massive open online courses (MOOCs) have launched a scale shift in higher education, with several individual MOOCs now boasting tens or hundreds of thousands of participants worldwide. Our MOOC on the principles of functional programming has more than 100,000 registered students to date, and boasts one of the highest rates of completion (19.2%) for its size. In this paper, we describe our experience organizing this popular MOOC, and demonstrate how providing innovative supporting tools (IDE plugins, testing frameworks, interactive build tools, automated cloud-based graders, style checkers) and considering key human-computer interaction factors potentially contributed to this markedly high completion rate. We collect an unprecedented volume of course statistics and survey results and have made them available, along with scripts for generating interactive web-based visualizations, as an open-source project

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