Degree-of-Interest Trees
Navigation of taxonomic abundances
The Degree-of-Interest (DOI) Tree technique was proposed by
Heer, Jeffrey, and Stuart K. Card. "DOITrees revisited: scalable,
space-constrained visualization of hierarchical data." Proceedings of
the working conference on Advanced visual interfaces. ACM, 2004.
as a principled strategy for laying out and navigating
large trees. The principle is used here for comparing
the abundance between taxonomic groups at varying levels
of locality.
The paper given above describes a number of additional useful
features, like breadcrumbs and symbolic labeling of
hidden subtrees, that have yet to be implemented in this view.
Guide
Clicking on nodes sets them to the highest interest and
recenters the screen around them. All ancestors of the
focus node are highlighted in purple.
The parameters in the left-hand box adjust which nodes are
displayed as well as how they are displayed. The minimum DOI
slider specifies the degree of locality in the
display. Dragging the slider to the left and right give more
global and local views, respectively. The minimum abundance
slider can be used to filter away nodes that are low
abundance; the aggressiveness of the filtering increases as
the slider moves to the right.
The node y and x-size parameters adjust how much space is
allocated to each node in the x and y direction. The smaller
the x-sizes are, the more nodes can be displayed on the
screen.
The gray search box at the bottom allows the user to search for
specific taxonomic labels. It highlights in read any paths to
nodes that match the query. For example, typing "lach"
highlights a path to the Lachnospiraceae family.