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

Dynamic Influence Networks for Rule-based Models

We introduce the Dynamic Influence Network (DIN), a novel visual analytics technique for representing and analyzing rule-based models of protein-protein interaction networks. Rule-based modeling has proved instrumental in developing biological models that are concise, comprehensible, easily extensible, and that mitigate the combinatorial complexity of multi-state and multi-component biological molecules. Our technique visualizes the dynamics of these rules as they evolve over time. Using the data produced by KaSim, an open source stochastic simulator of rule-based models written in the Kappa language, DINs provide a node-link diagram that represents the influence that each rule has on the other rules. That is, rather than representing individual biological components or types, we instead represent the rules about them (as nodes) and the current influence of these rules (as links). Using our interactive DIN-Viz software tool, researchers are able to query this dynamic network to find meaningful patterns about biological processes, and to identify salient aspects of complex rule-based models. To evaluate the effectiveness of our approach, we investigate a simulation of a circadian clock model that illustrates the oscillatory behavior of the KaiC protein phosphorylation cycle.Comment: Accepted to TVCG, in pres

Evaluation of two interaction techniques for visualization of dynamic graphs

Several techniques for visualization of dynamic graphs are based on different spatial arrangements of a temporal sequence of node-link diagrams. Many studies in the literature have investigated the importance of maintaining the user's mental map across this temporal sequence, but usually each layout is considered as a static graph drawing and the effect of user interaction is disregarded. We conducted a task-based controlled experiment to assess the effectiveness of two basic interaction techniques: the adjustment of the layout stability and the highlighting of adjacent nodes and edges. We found that generally both interaction techniques increase accuracy, sometimes at the cost of longer completion times, and that the highlighting outclasses the stability adjustment for many tasks except the most complex ones.Comment: Appears in the Proceedings of the 24th International Symposium on Graph Drawing and Network Visualization (GD 2016

An Evaluation of the Effortless Approach to Build Algorithm Animations with WinHIPE

AbstractThe use of algorithm visualizations in computer science education is not a new thing. Although there is a firm belief that graphical representations of algorithms are learning aids, empirical studies show that what is important is what the students do with the animations rather than what they see in them. In this paper we compare to kinds of interaction: viewing animations vs constructing animations. We have conducted a controlled experiment where a group of students (n=15) had to study an algorithm and complete a knowledge test about it and a subjective opinion questionnaire. Students were randomly divided in constructing and viewing groups. Results have been measured by means of learning outcomes, efficiency issues and student's subjective opinion. Results significantly evidence that builders obtained better results than viewers

Defining and evaluating conflictive animations for programming education : the case of Jeliot ConAn

A review of the practical uses of errors in education reveals three contexts where errors have been shown to help: teaching conceptual knowledge, changing students’ attitudes and promoting learning skills. Conflictive animations form a novel approach to teaching programming that follows a long tradition on research and development on program animation tools. Conflictive animations link the benefits of errors with program animation tools and programming education. This approach involves presenting to the students conflictive animations that do not animate faithfully the programs or concepts taught. Conflictive animations are versatile enough to cover the fundamental building blocks of programs such as operators, expressions and statements. With conflictive animations a novel set of learning activities can be introduced to computer science classes. This conflictive dimension of activities augments an engagement taxonomy for animation tools at all levels. They are an example of activities that promote critical thinking. A particular implementation of conflictive animations has been empirically evaluated aiming for ecological validity rather than statistical significance. Results indicate that students using conflictive animations improve their metacognitive skills, and, when compared to a control group, their conceptual knowledge improves at a better rate

Animating the evolution of software

The use and development of open source software has increased significantly in the last decade. The high frequency of changes and releases across a distributed environment requires good project management tools in order to control the process adequately. However, even with these tools in place, the nature of the development and the fact that developers will often work on many other projects simultaneously, means that the developers are unlikely to have a clear picture of the current state of the project at any time. Furthermore, the poor documentation associated with many projects has a detrimental effect when encouraging new developers to contribute to the software. A typical version control repository contains a mine of information that is not always obvious and not easy to comprehend in its raw form. However, presenting this historical data in a suitable format by using software visualisation techniques allows the evolution of the software over a number of releases to be shown. This allows the changes that have been made to the software to be identified clearly, thus ensuring that the effect of those changes will also be emphasised. This then enables both managers and developers to gain a more detailed view of the current state of the project. The visualisation of evolving software introduces a number of new issues. This thesis investigates some of these issues in detail, and recommends a number of solutions in order to alleviate the problems that may otherwise arise. The solutions are then demonstrated in the definition of two new visualisations. These use historical data contained within version control repositories to show the evolution of the software at a number of levels of granularity. Additionally, animation is used as an integral part of both visualisations - not only to show the evolution by representing the progression of time, but also to highlight the changes that have occurred. Previously, the use of animation within software visualisation has been primarily restricted to small-scale, hand generated visualisations. However, this thesis shows the viability of using animation within software visualisation with automated visualisations on a large scale. In addition, evaluation of the visualisations has shown that they are suitable for showing the changes that have occurred in the software over a period of time, and subsequently how the software has evolved. These visualisations are therefore suitable for use by developers and managers involved with open source software. In addition, they also provide a basis for future research in evolutionary visualisations, software evolution and open source development

Spreadsheet As An Algorithm Visualization Tool

This paper first presents the definition of algorithm visualization (AV) and its potential in increasing students’ engagement in the learning process according to Bloom’s taxonomy. Then it demonstrates in detail that not only can spreadsheet develop and support computational and algorithmic thinking, but it can also be used as an AV tool. Authors give examples as well on how learners can reach increasing levels of engagement using spreadsheet as an AV tool

Critters in the Classroom: A 3D Computer-Game-Like Tool for Teaching Programming to Computer Animation Students

The brewing crisis threatening computer science education is a well documented fact. To counter this and to increase enrolment and retention in computer science related degrees, it has been suggested to make programming "more fun" and to offer "multidisciplinary and cross-disciplinary programs" [Carter 2006]. The Computer Visualisation and Animation undergraduate degree at the National Centre for Computer Animation (Bournemouth University) is such a programme. Computer programming forms an integral part of the curriculum of this technical arts degree, and as educators we constantly face the challenge of having to encourage our students to engage with the subject. We intend to address this with our C-Sheep system, a reimagination of the "Karel the Robot" teaching tool [Pattis 1981], using modern 3D computer game graphics that today's students are familiar with. This provides a game-like setting for writing computer programs, using a task-specific set of instructions which allow users to take control of virtual entities acting within a micro world, effectively providing a graphical representation of the algorithms used. Whereas two decades ago, students would be intrigued by a 2D top-down representation of the micro world, the lack of the visual gimmickry found in modern computer games for representing the virtual world now makes it extremely difficult to maintain the interest of students from today's "Plug&Play generation". It is therefore especially important to aim for a 3D game-like representation which is "attractive and highly motivating to today's generation of media-conscious students" [Moskal et al. 2004]. Our system uses a modern, platform independent games engine, capable of presenting a visually rich virtual environment using a state of the art rendering engine of a type usually found in entertainment systems. Our aim is to entice students to spend more time programming, by providing them with an enjoyable experience. This paper provides a discussion of the 3D computer game technology employed in our system and presents examples of how this can be exploited to provide engaging exercises to create a rewarding learning experience for our students

A Runtime Software Visualization Environment

As software systems become more complex, so does the task of understanding them. To modify even a simple component of a complex system, at least a rudimentary understanding of the structure and behavior of the whole system is necessary. Although currently available development tools can provide a static representation of a complex system, these utilities are severely limited and prohibitively expensive. As a result, most programmers working on large software systems today resort to classic debuggers and time-consuming plain-text searches through hundreds or thousands of source files. This proposal describes a software development environment that uses static representations of hierarchically structured source code side by side with dynamic visualizations of software systems as they run. This environment provides an intuitive, visual means of easily comprehending complex systems, and has been provided as an open-source development tool for both professionals and students of software engineering