Proceedings of the Second Program Visualization Workshop, 2002

The Program Visualization Workshops aim to bring together researchers who design and construct program visualizations and, above all, educators who use and evaluate visualizations in their teaching. The first workshop took place in July 2000 at Porvoo, Finland. The second workshop was held in cooperation with ACM SIGCSE and took place at HornstrupCentret, Denmark in June 2002, immediately following the ITiCSE 2002 Conference in Aarhus, Denmark

A framework proposal for algorithm animation systems

The learning and analysis of algorithms and algorithm concepts are challenging to students due to the abstract and conceptual nature of algorithms. Algorithm animation is a form of technological support tool which encourages algorithm comprehension by visualising algorithms in execution. Algorithm animation can potentially be utilised to support students while learning algorithms. Despite widespread acknowledgement for the usefulness of algorithm animation in algorithm courses at tertiary institutions, no recognised framework exists upon which algorithm animation systems can be effectively modelled. This dissertation consequently focuses on the design of an extensible algorithm animation framework to support the generation of interactive algorithm animations. A literature and extant system review forms the basis for the framework design process. The result of the review is a list of requirements for a pedagogically effective algorithm animation system. The proposed framework supports the pedagogic requirements by utilising an independent layer structure to support the generation and display of algorithm animations. The effectiveness of the framework is evaluated through the implementation of a prototype algorithm animation system using sorting algorithms as a case study. This dissertation is successful in proposing a framework to support the development of algorithm animations. The prototype developed will enable the integration of algorithm animations into the Nelson Mandela Metropolitan University’s teaching model, thereby permitting the university to conduct future research relating to the usefulness of algorithm animation in algorithm courses

Facilitating algorithm visualization creation and adoption in education

The research question of this thesis is: How can we develop algorithm animations (AA) and AA systems further to better facilitate the creation and adoption of AA in education? The motivation for tackling this issue is that algorithm animation has not been widely used in teaching computer science. One of the main reasons for not taking full advantage of AA in teaching is the lack of time on behalf of the instructors. Furthermore, there is a shortage of ready-made, good quality algorithm visualizations. The main contributions are as follows: Effortless Creation of Algorithm Animation. We define a Taxonomy of Effortless Creation of Algorithm Animations. In addition, we introduce a new approach for teachers to create animations by allowing effortless on-the-fly creation of algorithm animations by applying visual algorithm simulation through a simple user interface. Proposed Standard for Algorithm Animation language. We define a Taxonomy of Algorithm Animation Languages to help comparing the different AA languages. The taxonomy and work by an international working group is used to define a new algorithm animation language, eXtensible Algorithm Animation Language, XAAL. Applications of XAAL in education. We provide two different processing approaches for using and producing XAAL animations with existing algorithm animation systems. In addition, we have a framework aiding in this integration as well as prototype implementations of the processes. Furthermore, we provide a novel solution to the problem of seamlessly integrating algorithm animations with hypertext. In our approach, the algorithm animation viewer is implemented purely with JavaScript and HTML. Finally, we introduce a processing model to easily produce lecture slides for a common presentation tool of XAAL animations

Algoritmus vizualizáció a tanítási gyakorlatban

Ez az előadás bemutatja az algoritmus vizualizáció (AV) történetét, külön kiemelve az oktatásmódszertani kérdéseket. Egy alapozó programozás kurzus hallgatóival elvégzett kétcsoportos pedagógiai vizsgálat is közlésre kerül, amely az AV eredményességét és az absztrakt gondolkodásra gyakorolt hatását mérte. A vizsgálat eredményei szerint eredményesebbek voltak az AV-t használó hallgatók

The Effectiveness of Aural Instructions with Visualisations in E-Learning Environments

Based on Mayer’s (2001) model for more effective learning by exploiting the brain’s dual sensory channels for information processing, this research investigates the effectiveness of using aural instructions together with visualisation in teaching the difficult concepts of data structures to novice computer science students. A small number of previous studies have examined the use of audio and visualisation in teaching and learning environments but none has explored the integration of both technologies in teaching data structures programming to reduce the cognitive load on learners’ working memory. A prototype learning tool, known as the Data Structure Learning (DSL) tool, was developed and used first in a short mini study that showed that, used together with visualisations of algorithms, aural instructions produced faster student response times than did textual instructions. This result suggested that the additional use of the auditory sensory channel did indeed reduce the cognitive load. The tool was then used in a second, longitudinal, study over two academic terms in which students studying the Data Structures module were offered the opportunity to use the DSL approach with either aural or textual instructions. Their use of the approach was recorded by the DSL system and feedback was invited at the end of every visualisation task. The collected data showed that the tool was used extensively by the students. A comparison of the students’ DSL use with their end-of-year assessment marks revealed that academically weaker students had tended to use the tool most. This suggests that less able students are keen to use any useful and available instrument to aid their understanding, especially of difficult concepts. Both the quantitative data provided by the automatic recording of DSL use and an end-of-study questionnaire showed appreciation by students of the help the tool had provided and enthusiasm for its future use and development. These findings were supported by qualitative data provided by student written feedback at the end of each task, by interviews at the end of the experiment and by interest from the lecturer in integrating use of the tool with the teaching of the module. A variety of suggestions are made for further work and development of the DSL tool. Further research using a control group and/or pre and post tests would be particularly useful

CHR^vis: Syntax and Semantics

The work in the paper presents an animation extension (CHR^{vis}) to Constraint Handling Rules (CHR). Visualizations have always helped programmers understand data and debug programs. A picture is worth a thousand words. It can help identify where a problem is or show how something works. It can even illustrate a relation that was not clear otherwise. CHR^{vis} aims at embedding animation and visualization features into CHR programs. It thus enables users, while executing programs, to have such executions animated. The paper aims at providing the operational semantics for CHR^{vis}. The correctness of CHR^{vis} programs is also discussed