Torre Zuk

Heuristics for information visualization evaluation

Heuristic evaluation is a well known discount evaluation technique in human-computer interaction (HCI) but has not been utilized in information visualization (InfoVis) to the same extent. While several sets of heuristics have been used or proposed for InfoVis, it is not yet known what kind of heuristics are useful for finding general InfoVis problems. We performed a meta-analysis with the goal of exploring the issues of heuristic evaluation for InfoVis. This meta-analysis concentrates on issues pertaining to the selection and organization of heuristics, and the process itself. For this purpose, we used three sets of previously published heuristics to assess a visual decision support system that is used to examine simulation data. The meta-analysis shows that the evaluation process and results have a high dependency on the heuristics and the types of evaluators chosen. We describe issues related to interpretation, redundancy, and conflict in heuristics. We also provide a discussion of generalizability and categorization of these heuristics.

Grounded evaluation of information visualizations

We introduce grounded evaluation as a process that attempts to ensure that the evaluation of an information visualization tool is situated within the context of its intended use. We discuss the process and scope of grounded evaluation in general, and then describe how qualitative inquiry may be a beneficial approach as part of this process. We advocate for increased attention to the field of qualitative inquiry early in the information visualization development life cycle, as it tries to achieve a richer understanding by using a more holistic approach considering the interplay between factors that influence visualizations, their development, and their use. We present three case studies in which we successfully used observational techniques to inform our understanding of the visual analytics process in groups, medical diagnostic reasoning, and visualization use among computational linguists.

Visualization of Uncertainty and Reasoning

This article gathers and consolidates the issues involved in uncertainty relating to reasoning and analyzes how uncertainty visualizations can support cognitive and meta-cognitive processes. Uncertainty in data is paralleled by uncertainty in reasoning processes, and while uncertainty in data is starting to get some of the visualization research attention it deserves, the uncertainty in the reasoning process is thus far often overlooked. While concurring with the importance of incorporating data uncertainty visualizations, we suggest also developing closely integrated visualizations that provide support for uncertainty in reasoning.

Visualizing temporal uncertainty in 3D virtual reconstructions

Uncertainty in various forms is prevalent throughout Archaeology. With archaeological site data in particular, the dating regularly has significant uncertainty. In this paper we present an application that enables integrating and visualizing the temporal uncertainty for multiple 3D archaeological data sets with different dating. We introduce a temporal time window for dealing with the uncertainty and review various visual cues appropriate for revealing the uncertainty within the time window. The interactive animation of the time window allows a unique exploration of the temporal uncertainty.

Exploration of uncertainty in bidirectional vector fields

While their importance is increasingly recognized, there remain many challenges in the development of uncertainty visualizations. We introduce two uncertainty visualizations for 2D bidirectional vector fields: one based on a static glyph and the other based on animated flow. These visualizations were designed for the task of understanding and interpreting anisotropic rock property models in the domain of seismic data processing. Aspects of the implementations are discussed relating to design, interaction, and tasks.

KeyStrokes: personalizing typed text with visualization

With the ubiquity of typed text, the style and much of the personality of handwriting has been lost from general communication. To counter this we introduce an artistic real-time visualization of typed messages that additionally captures and encodes aspects of an individuals unique typing style. The potential of our system to augment electronic communication was evaluated and the results are provided along with analysis of their implications for social visualization.

Interactive simulation and visualization using the GPU

Visual simulation can be efficiently performed using programmable graphics hardware. However, in utilizing hardware to maximize throughput, it is important not to constrain interactivity. We present a method of using the graphics hardware while maintaining full interactivity during simulation exploration. This interactivity involves: temporal exploration, data probing and modification, simulation model modification, and user defined visual metadata. Results are shown using our application for exploring a reaction-diffusion simulation.