Authors:
Ronak Etemadpour
1
;
Lars Linsen
2
;
Christopher Crick
1
and
Angus Forbes
3
Affiliations:
1
Oklahoma State University, United States
;
2
Jacobs Bremen University, Germany
;
3
University of Illinois at Chicago, Germany
Keyword(s):
Multidimensional Data Analysis, Task Taxonomy, Multidimensional Data Projection, User-centric Evaluation.
Related
Ontology
Subjects/Areas/Topics:
Abstract Data Visualization
;
Computer Vision, Visualization and Computer Graphics
;
General Data Visualization
;
High-Dimensional Data and Dimensionality Reduction
;
Interpretation and Evaluation Methods
;
Perception and Cognition in Visualization
;
Visualization Taxonomies and Models
Abstract:
When investigating multidimensional data sets with very large numbers of objects and/or a very large number
of dimensions, a variety of visualization methods can be employed in order to represent the data effectively
and to enable the user to explore the data at different levels of detail. A common strategy for encoding multidimensional
data for visual analysis is to use dimensionality reduction techniques that project data from higher
dimensions onto a lower-dimensional space. In this paper, we focus on projection techniques that output 2D
or 3D scatterplots which can then be used for a range of data analysis tasks. Existing taxonomies for multidimensional
data projections focus primarily on tasks in order to evaluate the human perception of class or
cluster separation and/or preservation. However, real-world data analysis of complex data sets often includes
other tasks besides cluster separation, such as: cluster identification, similarity seeking, cluster ranking, comparisons,
cou
nting objects, etc. A contribution of this paper is the identification of subtasks grouped into four
main categories of data analysis tasks. We believe that this user-centric task categorization can be used to
guide the organization of multidimensional data projection layouts. Moreover, this taxonomy can be used as
a guideline for visualization designers when faced with complex data sets requiring dimensionality reduction.
Our taxonomy aims to help designers evaluate the effectiveness of a visualization system by providing an
expanded range of relevant tasks. These tasks are gathered from an extensive study of visual analytics projects
across real-world application domains, all of which involve multidimensional projection. In addition to our
survey of tasks and the creation of the task taxonomy, we also explore in more detail specific examples of how
to represent data sets effectively for particular tasks. These case studies, while not exhaustive, provide a framework
for how specifically to reason about tasks and to decide on visualization methods. That is, we believe
that this taxonomy will help visualization designers to determine which visualization methods are appropriate
for specific multidimensional data projection tasks.
(More)