Thomas L. Naps

Exploring the role of visualization and engagement in computer science education

Visualization technology can be used to graphically illustrate various concepts in computer science. We argue that such technology, no matter how well it is designed, is of little educational value unless it engages learners in an active learning activity. Drawing on a review of experimental studies of visualization effectiveness, we motivate this position against the backdrop of current attitudes and best practices with respect to visualization use. We suggest a new taxonomy of learner engagement with visualization technology. Grounded in Blooms well-recognized taxonomy of understanding, we suggest metrics for assessing the learning outcomes to which such engagement may lead. Based on these taxonomies of engagement and effectiveness metrics, we present a framework for experimental studies of visualization effectiveness. Interested computer science educators are invited to collaborate with us by carrying out studies within this framework.

Evaluating the educational impact of visualization

The educational impact of visualization depends not only on how well students learn when they use it, but also on how widely it is used by instructors. Instructors believe that visualization helps students learn. The integration of visualization techniques in classroom instruction, however, has fallen far short of its potential. This paper considers this disconnect, identifying its cause in a failure to understand the needs of a key member in the hierarchy of stakeholders, namely the instructor. We describe these needs and offer guidelines for both the effective deployment of visualizations and the evaluation of instructor satisfaction. We then consider different forms of evaluation and the impact of student learning styles on learner outcomes.

Algorithm visualization in CS education: comparing levels of student engagement

Software technology for algorithm visualization (AV) has advanced faster than our understanding of how such technology impacts student learning. In this paper we present results of a multi-university study. We measured the effect of varying levels of student engagement with AV to learn simple sorting algorithms. These levels included: 1) not seeing any visualization, 2) simply viewing visualizations for a short period in the classroom, and 3) interacting directly with the visualizations for an extended period outside of the classroom. Our results show that learning increases as the level of student engagement increases. AV has a bigger impact on learning when students go beyond merely viewing a visualization and are required to engage in additional activities structured around the visualization. In particular, students who responded to questions integrated into the AV tool during their exploration of an algorithm showed the most improvement between a pretest and posttest.

JHAVE: supporting algorithm visualization

JHAVE fosters the use of algorithm visualization as an effective pedagogical tool for computer science educators, helping students to better understand algorithms. The Java-hosted algorithm visualization environment (JHAVE) is not an AV system itself but rather a support environment for a variety of AV systems (called AV engines by JHAVE). In broad terms, JHAVE gives such an engine a drawing context on which it can render its pictures in any way. In return, JHAVE provides the engine with effortless ways to synchronize its graphical displays with i) a standard set of VCR-like controls, ii) information and pseudocode windows, iii) input generators, iv) stop-and-think questions, and v) meaningful content generation tools.

Enhancing learning management systems to better support computer science education

Many individual instructors -- and, in some cases, entire universities -- are gravitating towards the use of comprehensive learning management systems (LMSs), such as Blackboard and Moodle, for managing courses and enhancing student learning. As useful as LMSs are, they are short on features that meet certain needs specific to computer science education. On the other hand, computer science educators have developed--and continue to develop-computer-based software tools that aid in management, teaching, and/or learning in computer science courses. In this report we provide an overview of current CS specific on-line learning resources and guidance on how one might best go about extending an LMS to include such tools and resources. We refer to an LMS that is extended specifically for computer science education as a Computing Augmented Learning Management System, or CALMS. We also discuss sound pedagogical practices and some practical and technical principles for building a CALMS. However, we do not go into details of creating a plug-in for some specific LMS. Further, the report does not favor one LMS over another as the foundation for a CALMS.

Algorithm visualization in computer science laboratories

This paper reports the results of an on-line survey conducted among computer science educators to examine effortless creation of algorithm visualizations. Based on the results, we give a proposal for measuring effortlessness in this sense. The aim is to enhance the understanding of the visualization tools adequate in computer science education.

Merging interactive visualizations with hypertextbooks and course management

As a report of a working group at ITiCSE 2006, this paper provides a vision of how visualizations and the software that generates them may be integrated into hypertextbooks and course management systems. This integration generates a unique synergy that we call a Visualization-based Computer Science Hypertextbook (VizCoSH). By borrowing features of both traditional hypertextbooks and course management systems, VizCoSHs become delivery platforms that address some of the reasons why visualizations have failed to find widespread use in education.The heart of the paper describes these features and explains, from both a student and teacher perspective, how each feature adds educational value to a visualization. In some cases, this value focuses on pedagogical issues, taking advantage of known strategies for making visualizations more engaging and effective. In other cases, the emphasis is on making it easier for teachers to use visualizations. A set of possible use scenarios and approaches for increasing interest in adopting a VizCoSH are also presented.

An overview of visualization: its use and design: report of the working group in visualization

This paper presents an overview of visualization in Computer Science instruction. It is broken down in the following fashion. First, we present the motivation for using visualization and visual techniques in instruction. This is followed by a discussion of when the use of visualization is most appropriate. We then consider a broad spectrum of uses of visualization in Computer Science instruction. This spectrum is organized from passive to active in terms of a student’s involvement with the visualization tools. Types of visualizations are then categorized. The remainder of the paper focuses more on design issues for instructional visualization tools. These design issues are first presented from the perspective of the instructor who is constructing the visualization tool for students and then from the perspective of the programmer who is creating visualization software. We close the paper with some suggestions on organizing and maintaining a Web-based repository of visualization tools for Computer Science instruction.

Using the WWW as the delivery mechanism for interactive, visualization-based instructional modules (report of the ITiCSE '97 working group on visualization)

Visualization has long been an important pedagogical tool in CS education. The widespread use of the Web and the introduction of Java, with its ability to present interactive animated applets and other types of animation, all provide opportunities to expand the availability of visualization-based teaching and learning tools. In addition, the Web introduces new opportunities not available in traditional settings.We start by identifying the types of learning objectives that can be supported by visualizations and the Web environment. Next we look at specific areas where the use of the Web enhances learning beyond the usual visualization, as well as at new learning and teaching paradigms supported by the Web. We then discuss a number of different mechanisms that can be used to deliver visualizations over the Web and new ways of managing displays in the Web-based environment. We point out both advantages and disadvantages of using the Web. A look into the future follows. We consider what changes and improvements we can expect and what specific activities we would like the CS community to undertake. We end with a brief survey of currently available Web-based visualization teaching tools and a commitment to maintain a list of links to these and other sites.

Development of XML-based tools to support user interaction with algorithm visualization

As a report of a working group at ITiCSE 2005, this paper represents a vision of the use of XML specifications and tools in algorithm visualization, particularly with regard to supporting user interaction. A detailed description is given of how an interesting event to be visualized is decomposed, combined with interactive questions, narratives, control flow code and metadata, and finally rendered into graphical primitive and transformation specifications. The heart of the paper is our discussion of XML specifications for content generation (the object being visualized), interactive questions, and graphical primitives and transformations, with briefer discussions of narratives and metadata. Examples are provided for each in an appendix, with fuller details to be published on an associated website that we hope will become a source of future standards in this area. In conclusion, the approach of the working group is discussed, and important remaining challenges are identified.