5 research outputs found
ProjectionPathExplorer: Exploring Visual Patterns in Projected Decision-Making Paths
In problem-solving, a path towards solutions can be viewed as a sequence of
decisions. The decisions, made by humans or computers, describe a trajectory
through a high-dimensional representation space of the problem. By means of
dimensionality reduction, these trajectories can be visualized in
lower-dimensional space. Such embedded trajectories have previously been
applied to a wide variety of data, but analysis has focused almost exclusively
on the self-similarity of single trajectories. In contrast, we describe
patterns emerging from drawing many trajectories---for different initial
conditions, end states, and solution strategies---in the same embedding space.
We argue that general statements about the problem-solving tasks and solving
strategies can be made by interpreting these patterns. We explore and
characterize such patterns in trajectories resulting from human and
machine-made decisions in a variety of application domains: logic puzzles
(Rubik's cube), strategy games (chess), and optimization problems (neural
network training). We also discuss the importance of suitably chosen
representation spaces and similarity metrics for the embedding.Comment: Final version; accepted for publication in the ACM TiiS Special Issue
on "Interactive Visual Analytics for Making Explainable and Accountable
Decisions
Constructing and Visualizing High-Quality Classifier Decision Boundary Maps dagger
Visualizing decision boundaries of machine learning classifiers can help in classifier design, testing and fine-tuning. Decision maps are visualization techniques that overcome the key sparsity-related limitation of scatterplots for this task. To increase the trustworthiness of decision map use, we perform an extensive evaluation considering the dimensionality-reduction (DR) projection techniques underlying decision map construction. We extend the visual accuracy of decision maps by proposing additional techniques to suppress errors caused by projection distortions. Additionally, we propose ways to estimate and visually encode the distance-to-decision-boundary in decision maps, thereby enriching the conveyed information. We demonstrate our improvements and the insights that decision maps convey on several real-world datasets