Institute for Visualization and Perception Research 1 © Copyright 1998 Haim Levkowitz Perception for visualization: From design to evaluation Victoria Interrante, U. Minn. Haim Levkowitz (chair), IVPR, UMass Lowell Hans-Peter Meinzer, DKFZ-Heidelberg, Germany

Institute for Visualization and Perception Research 2 © Copyright 1998 Haim Levkowitz Overview Purpose of collecting information Constantly growing... Need to understand how to... Challenges … Examples...

Institute for Visualization and Perception Research 3 © Copyright 1998 Haim Levkowitz Purpose of collecting information Present it to Analyze it by Human beings Constantly growing: amounts & complexity...

Institute for Visualization and Perception Research 4 © Copyright 1998 Haim Levkowitz Constantly growing... Amounts collected Complexity Information Analysis Need to understand how to...

Institute for Visualization and Perception Research 5 © Copyright 1998 Haim Levkowitz Need to understand how to... Increase comprehension Make analysis easier & efficient

Institute for Visualization and Perception Research 6 © Copyright 1998 Haim Levkowitz A presentation … An experience, not just an image... Aimed at humans Has to be designed...

Institute for Visualization and Perception Research 7 © Copyright 1998 Haim Levkowitz An experience, not just an image... User-directed, dynamic Multidisciplinary … Multisensory...

Institute for Visualization and Perception Research 8 © Copyright 1998 Haim Levkowitz Multidisciplinary... Graphics Imaging Psychology Man-machine interface Databases Multimedia

Institute for Visualization and Perception Research 9 © Copyright 1998 Haim Levkowitz Multisensory... Visual Auditory Tactile More?

Institute for Visualization and Perception Research 10 © Copyright 1998 Haim Levkowitz Has to be designed... Audience Question(s) / tasks... Contents Delivery

Institute for Visualization and Perception Research 11 © Copyright 1998 Haim Levkowitz Question(s) / tasks... Explore vs. Confirm E.g., detection vs. identification

Institute for Visualization and Perception Research 12 © Copyright 1998 Haim Levkowitz Perceptually-based presentation … Make perceptually effective … How?...

Institute for Visualization and Perception Research 13 © Copyright 1998 Haim Levkowitz Make perceptually effective … Understand perceptual processes … Harness them...

Institute for Visualization and Perception Research 14 © Copyright 1998 Haim Levkowitz Understand perceptual processes... Color Size Shape Texture Motion Sound

Institute for Visualization and Perception Research 15 © Copyright 1998 Haim Levkowitz Harness them... Data "Speak" for themselves Exploratory vs. confirmatory analyses Raise dimensionality MDMV

Institute for Visualization and Perception Research 16 © Copyright 1998 Haim Levkowitz How?... Substitute pre-conscious for conscious Pre-conscious … Conscious...

Institute for Visualization and Perception Research 17 © Copyright 1998 Haim Levkowitz Pre-conscious... Do not interfere with ability to think Parallel Hard-wired/entrained Fast Relentless Simultaneously w/conscious analysis

Institute for Visualization and Perception Research 18 © Copyright 1998 Haim Levkowitz Conscious... Interfere Serial Ad-hoc Slow Cause fatigue Distract from higher level analysis

Institute for Visualization and Perception Research 19 © Copyright 1998 Haim Levkowitz Challenges … Understand "perception"... Apply perception... Truth and accuracy obligation … Effectiveness Evaluation and verification...

Institute for Visualization and Perception Research 20 © Copyright 1998 Haim Levkowitz Understand "perception"... Lower-level vision (also audition, touch) Perception … Cognition … Aesthetics Emotional & cultural

Institute for Visualization and Perception Research 21 © Copyright 1998 Haim Levkowitz Perception... Color Shape Size Texture Motion Segmentation

Institute for Visualization and Perception Research 22 © Copyright 1998 Haim Levkowitz Cognition... Attention (pre-attentive vs. scrutiny; preconscious vs. conscious) Memory (iconic, short term, long term) Semantics & symbolism

Institute for Visualization and Perception Research 23 © Copyright 1998 Haim Levkowitz Apply perception... ==> Perceptually-based Representations … Rules & guidelines … Interaction ==> Presentations

Institute for Visualization and Perception Research 24 © Copyright 1998 Haim Levkowitz Representations... E.g., generalize pixels fi more info Visual Color Geometry … Motion Sound

Institute for Visualization and Perception Research 25 © Copyright 1998 Haim Levkowitz Geometry... Line orientation Area Volume Curvature Texture

Institute for Visualization and Perception Research 26 © Copyright 1998 Haim Levkowitz Rules & guidelines... Contrast Color Font Size Style

Institute for Visualization and Perception Research 27 © Copyright 1998 Haim Levkowitz Truth and accuracy obligation... Informing vs. entertaining Comprehension vs. aesthetics Informing ==> as truthful as possible Avoid misleading viewers E.g., Brooks (Vis '93): background music...

Institute for Visualization and Perception Research 28 © Copyright 1998 Haim Levkowitz E.g., Brooks (Vis '93): background music... What message? Lower SNR, unless Intentional Accurate Show business

Institute for Visualization and Perception Research 29 © Copyright 1998 Haim Levkowitz Evaluation and verification … Tasks … Data...

Institute for Visualization and Perception Research 30 © Copyright 1998 Haim Levkowitz Tasks... Presence / absence Edge / boundary Target / blob Location Classification

Institute for Visualization and Perception Research 31 © Copyright 1998 Haim Levkowitz Data... Real … Synthesized...

Institute for Visualization and Perception Research 32 © Copyright 1998 Haim Levkowitz Real... "Truth" unknown E.g., Satellite Water vs. land Medical Normal vs. abnormal

Institute for Visualization and Perception Research 33 © Copyright 1998 Haim Levkowitz Synthesized... "Truth" known Statistics Not real

Institute for Visualization and Perception Research 34 © Copyright 1998 Haim Levkowitz Examples... Medical Earth science Reconnaissance Presentations

Institute for Visualization and Perception Research 35 © Copyright 1998 Haim Levkowitz Conclusions... What is information presentation Perceptually-based information presentation Design Evaluation & verification Challenges Examples

Institute for Visualization and Perception Research 36 © Copyright 1998 Haim Levkowitz Moral... Present to inform, not to impress; if you inform, you will impress after Fred Brooks Keynote Address Visualization ’93

Institute for Visualization and Perception Research 37 © Copyright 1998 Haim Levkowitz Emerging discipline Eick: "Graphically displaying text" J. Comp. & Graphical Statistics Four progress stages … Wong & Bergeron, 1995: "30 years of MDMV Vis” Four stages of MDMV Vis. Development...

Institute for Visualization and Perception Research 38 © Copyright 1998 Haim Levkowitz Four progress stages... Skilled artisans: Craft Practical experience guidelines Researchers: Scientific principles & theories Engineers: Production rules Widely available technology

Institute for Visualization and Perception Research 39 © Copyright 1998 Haim Levkowitz Four stages of MDMV Vis. Development... Pre-1976: The Searching Stage : The Awakening Stage : The Discovery Stage 1992-present: The Elaboration Stage

Institute for Visualization and Perception Research 40 © Copyright 1998 Haim Levkowitz Tutorial overview Levkowitz: Vision & color; evaluation and verification Interrante: Visual perception; cognitive issues Meinzer: Perception in image generation and understanding Summary, discussions, future directions