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  1. With the advent of online educational platforms and the advances in pedagogical technologies, self-directed learning has emerged as one of the most popular modes of learning. Distance education---elevated by the COVID-19 pandemic---involves methods of instruction through a variety of remote activities which often rely on educational videos for mastery. In the absence of direct student engagement, the asynchronous nature of remote activities may deteriorate the quality of education for learners. Students often have an illusion of skill acquisition after watching videos, which results in overestimation of abilities and skills. We focus on the efficacy of skill acquisition through interactive technologies and assess their impact on computational thinking in comparison with delivery through other traditional media (e.g. videos and texts). In particular, we investigate the relationship between actual learning, perception of learning, and learners' confidence in adult learners. Our results reveal intriguing observations about the role of interactivity and visualization and their implications on the pedagogical design for self-directed learning modules. 
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  2. Crossley, Scott ; Popescu, Elvira (Ed.)
    Automated program repair is a promising approach to deliver feedback to novice learners at scale. CLARA is an effective repairer that uses a correct program to fix an incorrect program. CLARA suffers from two main issues: rigid matching and lack of support for typical constructs and tasks in introductory programming assignments. We present several modifications to CLARA to overcome these problems. We propose approximate graph matching based on semantic and topological information of the programs compared, and modify CLARA’s abstract syntax tree processor and interpreter to support new constructs and tasks like reading from/writing to console. Our experiments show that, thanks to our modifications, we can apply CLARA to real-world programs. Also, our approximate graph matching allows us to repair many incorrect programs that are not repaired using rigid program matching. 
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  3. Cristea, Alexandra I. ; Troussas, Christos (Ed.)
    The number of introductory programming learners is increasing worldwide. Delivering feedback to these learners is important to support their progress; however, traditional methods to deliver feedback do not scale to thousands of programs. We identify several opportunities to improve a recent data-driven technique to analyze individual program statements. These statements are grouped based on their semantic intent and usually differ on their actual implementation and syntax. The existing technique groups statements that are semantically close, and considers outliers those statements that reduce the cohesiveness of the clusters. Unfortunately, this approach leads to many statements to be considered outliers. We propose to reduce the number of outliers through a new clustering algorithm that processes vertices based on density. Our experiments over six real-world introductory programming assignments show that we are able to reduce the number of outliers and, therefore, increase the total coverage of the programs that are under evaluation. 
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  4. Cristea, Alexandra I. ; Troussas, Christos (Ed.)
    Supporting novice programming learners at scale has become a necessity. Such a support generally consists of delivering automated feedback on what and why learners did incorrectly. Existing approaches cast the problem as automatically repairing learners’ incorrect programs; specifically, data-driven approaches assume there exists a correct program provided by other learner that can be extrapolated to repair an incorrect program. Unfortunately, their repair potential, i.e., their capability of providing feedback, is hindered by how they compare programs. In this paper, we propose a flexible program alignment based on program dependence graphs, which we enrich with semantic information extracted from the programs, i.e., operations and calls. Having a correct and an incorrect graphs, we exploit approximate graph alignment to find correspondences at the statement level between them. Each correspondence has a similarity attached to it that reflects the matching affinity between two statements based on topology (control and data flow information) and semantics (operations and calls). Repair suggestions are discovered based on this similarity. We evaluate our flexible approach with respect to rigid schemes over correct and incorrect programs belonging to nine real-world introductory programming assignments. We show that our flexible program alignment is feasible in practice, achieves better performance than rigid program comparisons, and is more resilient when limiting the number of available correct programs. 
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  5. null (Ed.)