Evaluation of a Bundling Technique for Parallel Coordinates

We describe a technique for bundled curve representations in parallel-coordinates plots and present a controlled user study evaluating their effectiveness. Replacing the traditional C^0 polygonal lines by C^1 continuous piecewise Bezier curves makes it easier to visually trace data points through each coordinate axis. The resulting Bezier curves can then be bundled to visualize data with given cluster structures. Curve bundles are efficient to compute, provide visual separation between data clusters, reduce visual clutter, and present a clearer overview of the dataset. A controlled user study with 14 participants confirmed the effectiveness of curve bundling for parallel-coordinates visualization: 1) compared to polygonal lines, it is equally capable of revealing correlations between neighboring data attributes; 2) its geometric cues can be effective in displaying cluster information. For some datasets curve bundling allows the color perceptual channel to be applied to other data attributes, while for complex cluster patterns, bundling and color can represent clustering far more clearly than either alone

Tools and theory to improve data analysis

This thesis proposes a scientific model to explain the data analysis process. I argue that data analysis is primarily a procedure to build un- derstanding and as such, it dovetails with the cognitive processes of the human mind. Data analysis tasks closely resemble the cognitive process known as sensemaking. I demonstrate how data analysis is a sensemaking task adapted to use quantitative data. This identification highlights a uni- versal structure within data analysis activities and provides a foundation for a theory of data analysis. The model identifies two competing chal- lenges within data analysis: the need to make sense of information that we cannot know and the need to make sense of information that we can- not attend to. Classical statistics provides solutions to the first challenge, but has little to say about the second. However, managing attention is the primary obstacle when analyzing big data. I introduce three tools for managing attention during data analysis. Each tool is built upon a different method for managing attention. ggsubplot creates embedded plots, which transform data into a format that can be easily processed by the human mind. lubridate helps users automate sensemaking out- side of the mind by improving the way computers handle date-time data. Visual Inference Tools develop expertise in young statisticians that can later be used to efficiently direct attention. The insights of this thesis are especially helpful for consultants, applied statisticians, and teachers of data analysis

A sketching-oriented design method for information visualization software.

The aim of this research is to describe a useful approach for supporting creativity and problem-solving in the design of Information Visualization software. This type of software is useful for helping people to understand large or complex collections of data by making the data easier to see and use. Because it can be so helpful, many people are motivated to create visualization software to address their own unique problems of understanding data. However, the techniques which visualizations use to enhance cognition of data are not widely known. Also, there are currently few resources which comprehensively describe a method for designing novel visualizations. Consequently, people who seek to build new Information Visualization tools are left to consult design examples, guidelines, and reference models, which do not adequately describe the visualization design process. The key question of the research concerns how Information Visualization methodologies should account for representation of the user, existing visualization design knowledge, and sketching. Given that the current methods of Information Visualization design are incomplete and show evidence of significant shortcomings, how can novice visualization design teams bridge these gaps by using methods from other design disciplines to successfully create effective visualizations To investigate this question, several studies were conducted. Also, a design methodology called So Viz was developed. It incorporates a participatory design approach, using sketching and visualization design patterns to support creativity and problem-solving. A prototype was designed using the SoViz approach. The key contributions of this thesis are results which show that Information Visualization designers can benefit from using this method. The thesis presents the results of using SoViz to create an Information Visualization prototype and describes the theoretical consequences for Information Visualization methodology

The interactive stardinates : an information visualization technique applied in a multiple view system

Zsfassung in dt. Sprache12