A Review and Taxonomy of Distortion-Oriented Presentation Techniques Y.K Leung and M.D. Apperley Presentation by Sean Lynch

Problem In most computer systems, small viewing space Problems: locating items interpreting items determining relationships between items Two techniques: distortion-oriented and non- distortion

Non-distortion Techniques Display portion of data Divide information space into portions Arrange in a way for presentation

Problems with non- distortion Inadequate context for navigating large-scale information Solution: distortion-oriented techniques

Distortion Techniques Allow user to examine local areas in greater detail Fast-growing field with numerous techniques Taxonomy and unified theory needed

Distortion(2) Essence: local detail and global context

Polyfocal Display

Bifocal Display

Fisheye View(Furnas) Main technique is thresholding

Fisheye View(Hollands et al.) Used to represent subway network to compare fisheye vs. scrolling Three tasks: route task, locate/route task, itinerary task Generally closer to Bifocal than Furnas

Fisheye View(Mitta) Presentation for aircraft maintenance data Certain components were suppressed to increase focus Information suppressing technique

Perspective Wall

Graphical Fisheye

Taxonomy Techniques can be broken into two categories: Piece-wise Continuous: Bifocal, Perspective Wall Continuous: Polyfocal, Fisheye Piece-wise can be further broken into constant or varying

Unified Theory Treat displayed information as if on rubber sheet Consider bifocal display: a, b, c marked on sheet Sheet is stretched and distorted

A Framework for unifying presentation space M.S.T. Carpendale and Catherine Montagnese

Elastic Presentation Framework Unified framework for distortion and non-distortion based presentation methods Method of relating distinct methods into a single interface

Basic Geometric Concepts

Multi-Scale Presentations Made possible by inclusion of drop-off functions Focal regions set to a particular degree of magnification

Folding Repositioning of foci in lens Shear viewer-aligned vectors

Distance Metrics On Lp metrics, can provide different drop off functions

United Framework Framework provides method of relating distinct methods Allows for more than one presentation in a single interface Lens library offers a range of distortion choices.

Gaussian Lens Bell-shape Advantage: gentle focal integration Characteristics: focal magnification, good visual integration

Lens Library From left to right: Gaussian, Cosine, Hemisphere, Linear, Inverse Cosine, Manhattan Top row is focus to distortion Bottom row is distortion to context

Insets and Offsets Inset is a selected sub-region that is magnified Achieved at cost of local-context Offset is a selected sub-region moved and magnified Occludes other regions

Detail-In-Context Presentations and Zooming Typical drop-off functions use both x and y for distance function Can use either only x or only y

EPF Library Representation and presentation kept distinct Lenses have precise magnification control and positioning All lenses can be folded

Conclusions! Presented a taxonomy and unified theory of distortion- oriented presentation techniques Presented a unified framework for presentation spaces, with many different distortion techniques included

ANY QUESTIONs?