| 1. |
- Begum, Marjahan, et al.
(author)
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Empirical Evaluation of a Differentiated Assessment of Data Structures: The Role of Prerequisite Skills
- 2023
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In: Informatics in Education. An International Journal. - Vilnius : Vilnius University. - 1648-5831 .- 2335-8971. ; 23, s. 57-99
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Journal article (peer-reviewed)abstract
- There can be many reasons why students fail to answer correctly to summative tests in advanced computer science courses: often the cause is a lack of prerequisites or misconceptions about topics presented in previous courses. One of the ITiCSE 2020 working groups investigated the possibility of designing assessments suitable for differentiating between fragilities in prerequisites (in particular, knowledge and skills related to introductory programming courses) and advanced topics. This paper reports on an empirical evaluation of an instrument focusing on data structures, among those proposed by the ITiCSE working group. The evaluation aimed at understanding what fragile knowledge and skills the instrument is actually able to detect and to what extent it is able to differentiate them. Our results support that the instrument is able to distinguish between some specific fragilities (e.g., value vs. reference semantics), but not all of those claimed in the original report. In addition, our findings highlight the role of relevant skills at a level between prerequisite and advanced skills, such as program comprehension and reasoning about constraints. We also suggest ways to improve the questions in the instrument, both by improving the distractors of the multiple choice questions, and by slightly changing the content or phrasing of the questions. We argue that these improvements will increase the effectiveness of the instrument in assessing prerequisites as a whole, but also to pinpoint specific fragilities.
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| 2. |
- Björn, Camilla, et al.
(author)
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It’s Okay Because I Worked Really Hard! – Student Justifications for Questionable Collaboration while Solving Computer Labs
- 2022
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In: 2022 IEEE Frontiers in Education Conference (FIE). - : IEEE. - 9781665462440 - 9781665462457
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Conference paper (peer-reviewed)abstract
- In this full research paper we examine questionable collaboration from a student perspective. Collaborating while solving computer lab assignments is often considered an important part when learning computer science, as it allows students to discuss their work, while also practicing working together. However, it also introduces risks, such as students collaborating in ways negatively impacting their learning outcomes and leading to inaccurate grading. Hence it is important to work towards reducing the use of these poor collaborative practices. In order to ameliorate the problem with academic misconduct, we need to understand students’ justifications for deviating from acceptable practices. In this paper we therefore investigate how students justify their collaborative practices during computer lab assignments in situations they experience as questionable. The justifications were collected through 15 semi-structured interviews with students experienced in pair programming, majoring in computer science and other technical fields from two large well-known European universities.The justifications from the interviews were analysed using phenomenography resulting in seven categories: external pressure, lack of interest, spending time on the assignment, understanding the end product, contributing to the process, learning from the assignment and reflecting on the purpose of the learning. These describe in which situations students might deviate from the rules and can be used by institutions to prevent such behavior.
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| 3. |
- Haglund, Pontus, et al.
(author)
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Understanding Students’ Failure to use Functions as a Tool for Abstraction – An Analysis of Questionnaire Responses and Lab Assignments in a CS1 Python Course
- 2021
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In: Informatics in Education. An International Journal. - : Vilnius University Press. - 1648-5831 .- 2335-8971. ; 20:4, s. 583-614
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Journal article (peer-reviewed)abstract
- Controlling complexity through the use of abstractions is a critical part of problem solving in programming. Thus, becoming proficient with procedural and data abstraction through the use of user-defined functions is important. Properly using functions for abstraction involves a number of other core concepts, such as parameter passing, scope and references, which are known to be difficult. Therefore, this paper aims to study students proficiency with these core concepts, and students ability to apply procedural and data abstraction to solve problems. We collected data from two years of an introductory Python course, both from a questionnaire and from two lab assignments. The data shows that students had difficulties with the core concepts, and a number of issues solving problems with abstraction. We also investigate the impact of using a visualization tool when teaching the core concepts.
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| 4. |
- Nelson, Greg L., et al.
(author)
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Differentiated Assessments for Advanced Courses that Reveal Issues with Prerequisite Skills : A Design Investigation
- 2020
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In: ITICSE-WGR'20. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450382939 ; , s. 75-129
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Conference paper (peer-reviewed)abstract
- Computing learners may not master basic concepts, or forget them between courses or from infrequent use. Learners also often struggle with advanced computing courses, perhaps from weakness with prerequisite concepts. One underlying challenge for researchers and instructors is determining the reason why a learner gets an advanced question wrong. Was the wrong answer because the learner lacked prerequisite skills, has not mastered the advanced skill, or some combination of the two? We contribute a design investigation into how to create differentiated questions which diagnose prerequisite and advanced skills at the same time. We focused on tracing and related skills as prerequisites, and on advanced object-oriented programming, concurrency, algorithm and data structures as the advanced skills. We conducted an inductive qualitative analysis of existing assessment questions from instructors and from a concept inventory with a validity argument (the Basic Data Structures Inventory). We found dependencies on a variety of prerequisite knowledge and mixed potential for diagnosing difficulties with prerequisites. Inspired by this analysis, we developed examples of differentiated assessments and reflected on design principles for creating/modifying assessments to better assess both advanced and prerequisite skills. Our example differentiated assessment questions and methods help enable research into how prerequisites skills affect learning of advanced concepts. They also may help instructors better understand and help learners with varying prerequisite knowledge, which may improve equity of learning outcomes. Our work also raises theoretical questions about what assessments really assess and how separate advanced topics and prerequisite skills are.
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| 5. |
- Strömbäck, Filip, et al.
(author)
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A Student's View of Concurrency : A Study of Common Mistakes in Introductory Courses on Concurrency
- 2019
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In: Proceedings of the 2019 ACM Conference on International Computing Education Research. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450361859 ; , s. 229-237
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Conference paper (peer-reviewed)abstract
- This paper investigates common misconceptions held by students regarding concurrency in order to better understand how concurrency education can be improved in the future. As a part of the exam in two courses on concurrency and operating systems, students were asked to identify and eliminate any concurrency issues in a piece of code as a part of their final exam. Different types of mistakes were identified and the 216 answers were sorted into categories accordingly. The results presented in this paper show that while most students were able to identify the cause of an issue given its symptoms, only approximately half manage to successfully eliminate the concurrency issues. Many of the incorrect solutions fail to associate shared data with a synchronization primitive, e.g. using one lock to protect multiple instances of a data structure, or multiple locks to protect the same instance in different situations. This suggests that students may not only have trouble dealing with concepts related to concurrency, but also more fundamental concepts related to the underlying computational model. Finally, this paper proposes possible explanations for the students' mistakes in terms of improper mental models, and suggests types of problems that highlight the issues with these mental models to improve students' understanding of the subject.
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| 6. |
- Strömbäck, Filip, et al.
(author)
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A Weak Memory Model in Progvis: Verification and Improved Accuracy of Visualizations of Concurrent Programs to Aid Student Learning
- 2022
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In: Koli Calling '22: Proceedings of the 22nd Koli Calling International Conference on Computing Education Research. - New York, NY, USA : ACM Publications. - 9781450396165
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Conference paper (peer-reviewed)abstract
- Previous research has shown that many students struggle with solving small concurrency problems after their first course on concurrency. A possible reason for this is that students do not have a suitable mental model of the semantics of the underlying programming language, and are therefore not able to properly reason about the program’s behavior. One way to help students learn concurrency and improve their mental model is through the use of visualization tools. Progvis is one such visualization tool that is not only aimed at concepts related to concurrency, but also provides an accurate visualization of more fundamental concepts to illustrate how they interact with concurrency. In previous work, the authors of Progvis performed a small-scale evaluation of the tool, and highlighted some areas of improvement. In this paper, we address these shortcomings by improving the memory model visualized by Progvis and implementing a model checker. We also evaluate Progvis on a larger scale by incorporating it into a course on concurrency and operating systems, which allows assessing whether using Progvis aids students in learning concurrency. The results indicate that Progvis (with our improvements) is successful in helping students realize how concurrency interacts with more fundamental concepts, and that students find it useful in helping them understand the content of the concurrency assignments.
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| 7. |
- Strömbäck, Filip, et al.
(author)
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Exploring Students’ Understanding of Concurrency : A Phenomenographic Study
- 2020
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In: Proceedings of SIGCSE ’20. - New York, NY, USA : ACM Publications. - 9781450367936
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Conference paper (peer-reviewed)abstract
- This paper continues previous efforts in understanding the problemsstudents face when learning concurrency. In this paper, weexplore students’ understanding of the subject using phenomenographyin order to gain insights that can aid in explaining the underlyingcauses for common student mistakes in concurrency, whichhas been studied in depth previously. Students’ experience of concurrencyand critical sections were analyzed using a phenomenographicstudy based on interviews with students attending one oftwo courses on concurrency and operating systems. We present6 categories describing students’ experience of concurrency, and4 categories describing students’ experience of critical sections inthis paper. Furthermore, these categories are related to previousresults, both to explore how misconceptions in the categores relateto student mistakes and to estimate how common it is for eachcategory to be discerned.
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| 8. |
- Strömbäck, Filip, et al.
(author)
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Pilot Study of Progvis : A Visualization Tool for Object Graphs and Concurrency via Shared Memory
- 2022
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In: PROCEEDINGS OF THE 24TH AUSTRALASIAN COMPUTING EDUCATION CONFERENCE, ACE 2022. - New York : Association for Computing Machinery (ACM). - 9781450396431 ; , s. 123-132
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Conference paper (peer-reviewed)abstract
- Concurrency and synchronization are two topics that are becomingincreasingly important for computer science students due to thehigh number of cores available in most modern devices. These aretopics that many students struggle with at first, perhaps partiallydue to the inherent nondeterminism and the difficulty to test forabsence of race conditions. Furthermore, previous research indicate that some common mistakes when working with concurrencymight be due students not connecting the concurrency concepts(such as synchronization) to the data that needs to be protected,especially when pointers and references are involved.To address these issues, we propose Progvis, which is a visualization tool aimed specifically at concurrency using the sharedmemory model. It provides a detailed visualization of objects inmemory and their relation to the running threads in order to helpstudents connect concurrency issues with the affected data. Wehave performed an initial, small scale evaluation on whether usingthe tool helps students solve synchronization problems during voluntary problem-solving sessions. The preliminary results indicatethat students who used the tool did indeed perform better.
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| 9. |
- Strömbäck, Filip
(author)
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Storm: A Language Platform for Interacting and Extensible Languages (Tool Demo)
- 2018
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In: PROCEEDINGS OF THE 11TH ACM SIGPLAN INTERNATIONAL CONFERENCE ON SOFTWARE LANGUAGE ENGINEERING (SLE 18). - New York, NY, USA : ASSOC COMPUTING MACHINERY. - 9781450360296 ; , s. 60-64
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Conference paper (peer-reviewed)abstract
- The ability to extend programming languages with domain-specific concepts is becoming an essential technology for developing complex software. However, many domain-specific languages are implemented in a way that interact poorly with the host language. There are a number of tools that aim to improve the situation by simplifying the creation of domain-specific languages, and allow easier interactions between the host language and the domain-specific language. However, many of these tools are limited to a single host language, and rarely allow extending the language used for language creation. To improve the situation, we created the language platform Storm, which aims to make the creation and usage of multiple extensible languages easy and seamless. This is accomplished by means of a shared, standardized namespace and in-process code generation, which gives Storm a high degree of extensibility, making it possible to extend or replace the built-in languages at will.
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| 10. |
- Strömbäck, Filip
(author)
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Students Views of Concurrency and Synchronization
- 2019
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In: 19TH KOLI CALLING CONFERENCE ON COMPUTING EDUCATION RESEARCH (KOLI CALLING 2019). - New York, NY, USA : ACM Digital Library. - 9781450377157
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Conference paper (peer-reviewed)abstract
- This extended abstract describes our ongoing effort to support students learning and understanding of concurrency and synchronization. We have identified and quantified some of the areas that appear to be problematic to students, and are in the process of further examining underlying causes of these problematic areas. We then aim to utilize this knowledge to suggest interventions to existing approaches in order to better support students learning of the problematic areas in concurrency and evaluate the results of the interventions.
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