GEO DATA MANAGEMENT Dr. Kristien Ooms; Ghent University - PowerPoint PPT Presentation

EYE TRACKING IN GEO DATA MANAGEMENT Dr. Kristien Ooms; Ghent University Kristien.Ooms@UGent.be

Time Type Trial L POR X [px] L POR Y [px] 15256356851 SMP 1 589,64 590,82 W HAT IS EYE TRACKING ? 15256365267 SMP 1 586,6 587,1 15256373592 SMP 1 824,04 396,63 15256390210 SMP 1 589,08 584,7 15256398588 SMP 1 592,91 580,93 15256406933 SMP 1 588,32 578,83 15256423568 SMP 1 594,35 580,26 ▪ Tracking the user’s eye movements 15256431942 SMP 1 594,57 579,7 15256440305 SMP 1 598,26 575,05 • Sampling rate (times/second) 15256448557 SMP 1 598,33 571,11 15256456954 SMP 1 597,96 569,4 15256465310 SMP 1 597,92 571,55 • Current location of eyes on screen/picture/etc. 15256481930 SMP 1 600,35 570,2 15256490314 SMP 1 601,55 571,8 • (x,y,t) → ‘ raw data’ 15256498681 SMP 1 603,14 568,78 ▪ Metrics and measurements • Deriving meaningful metrics from raw data - fixations, saccades, smooth pursuit ▪ Study design? • Medium: paper, screen, etc. ? • Topic: VR, websites, simulators, maps, etc. • Analysis: qualitative, quantitative, visual, statistical, etc. Eye Tracking for GeoDataManagement - Kristien Ooms 2

… A LITTLE BIT OF HISTORY ▪ Earliest research: 1880 – 1920 • Basis facts about eye movement discovered ▪ Phase with more applied focus, little research • Buswell : “How people look at pictures” (1935 ) • Tinker (1946) - Cannot learn much from eye tracking data Source: http://psych.wfu.edu/art_ schirillo/articles/Buswell,%201935.pdf - Limits of technology • Fits et. al (1950) - Study eye movements of pilots in cockpit - First use in usability engineering ▪ Clear visualization of eye movements • Yarbus (1967) • Shows importance of eye movement recordings Yarbus (1967) Eye Tracking for GeoDataManagement - Kristien Ooms 4

… A LITTLE BIT OF HISTORY ▪ Recent evolution • 1970s: - Improvements in eye movement recording systems - Advances in psychological theory • 1980s:  Use of eye tracking in real time - Human-Computer interaction -Disabled users • 1990s  Solving usability problems -Internet, websites, emails, video-conferencing , … Eye Tracking for GeoDataManagement - Kristien Ooms 5

W HAT IS EYE TRACKING ? ▪ Video-based combined pupil and corneal reflection • Gives ‘point of regard ’ (POR) measurements! - Point where user is looking - Gaze position - Pixel coordinates – screen coordinates • Corneal reflections (from infra-red light source) - Purkinje reflections or images - Eye rotations: relative positional difference with pupil center - Appropriate callibration: determining user’s POR Eye Tracking for GeoDataManagement - Kristien Ooms 6

W HAT IS EYE TRACKING ? ▪ Video-based combined pupil and corneal reflection Eye Tracking for GeoDataManagement - Kristien Ooms 7

… D EMO … ▪ Measurements: • Points Of Regard at certain sampling rate - Calibration! - x, y: screen coordinates - Timestamp - Huge amount of ‘ raw data’ • Deriving metrics: - Fixations, Saccades, (Smooth Pursuit) DESIGNING AND CONDUCTING USER RESEARCH 8

W HAT IS EYE TRACKING ? ▪ Metrics: • Fixations - Stable relative position pupil – corneal reflection  dispersion = ??? (40px; 0.5 ° visual angle ; …) - During certain period  minimum duration = ??? (80 – 150 ms) • Saccades: - Rapid eye movements - Reposition of fovea - Person does not ‘ see ’ anything during saccade Eye Tracking for GeoDataManagement - Kristien Ooms 9

W HAT IS EYE TRACKING ? ▪ Metrics → meaning? • Link eye movements - attentive behavior - Can shift attention without movement of the eyes! - Central and peripheral vision - Attention precedes a saccade to a certain location - Complex task  link is very tight - Need of peripheral vision - Need of attention Eye Tracking for GeoDataManagement - Kristien Ooms 10

W HAT IS EYE TRACKING ? ▪ Metrics → meaning? • Link eye movements - attentive behavior • Data Interpretation “ Information processing is guided by higher level mental processes . When we construct our perception drawing on our past experiences and expectations ” “ The most basic sensation and perception . Entry Level” sensory analysis ” Eye Tracking for GeoDataManagement - Kristien Ooms 11

W HAT IS EYE TRACKING ? ▪ References: • Book of - Holmqvist et al. (2011) - Duchowski et al. (2007) • Jacob & Karn (2003) - 20 different usability studies - Most commonly used metrics: ∙ Number of fixations, overall ∙ Gaze % (proportion of time) on each of the AOIs ∙ Fixation duration mean, overall ∙ Number of fixations on each of the AOI ∙ Gaze duration mean, on each of the AOI ∙ Fixation rate,overall (fixation/saccades) Eye Tracking for GeoDataManagement - Kristien Ooms 12

W HAT IS EYE TRACKING ?  Related to Fixations (Overview by Poole & Ball, 2005) Eye Tracking for GeoDataManagement - Kristien Ooms 13

M ETRICS & M EANING ▪ Related to Saccades (Overview by Poole & Ball, 2005) Eye Tracking for GeoDataManagement - Kristien Ooms 14

S TUDY D ESIGN ▪ Other methods • Qualitative vs. Quantitative • Questionnaires • Thinking aloud • Response time measurements • Sketching • Scoring • Mouse & keyboard logging • Observation • Interview • EEG • … Eye Tracking for GeoDataManagement - Kristien Ooms 15

S TUDY D ESIGN  Software • Setting up experiment • Recording data • Interpretation ‘ raw ’ data • Analyses • Vendor specific • Open Source • Statistical Packages • Spatial analyses Eye Tracking for GeoDataManagement - Kristien Ooms 16

EYE TRACKING AT THE DEPARTMENT OF GEOGRAPHY, GHENT UNIVERSITY PROF. DR. PHILIPPE DE MAEYER PROF. DR. NICO VAN DE WEGHE PROF. DR. VEERLE VAN EETVELDE DR. KRISTIEN OOMS DR. RASHA DEEB LIEN DUPONT ANNELIES INCOUL PEPIJN VIAENE LIESELOT LAPON …

L ANDSCAPE PERCEPTION Lien Dupont Which elements in a landscape catch the attention and in which context are they most eye-catching? Important for the location of new infrastructures Observations of landscapes are influenced by… Landscape Observer Representation Eye Tracking for GeoDataManagement - Kristien Ooms 18

L ANDSCAPE PERCEPTION  How do people observe landscapes in general? • Influence of the photograph properties? Experiment 1 ‒ Focal length, horizontal and vertical view angles • Influence of the landscape characteristics? ‒ Degree of openness ‒ Degree of heterogeneity Experiment 2 • Influence of the social/professional background of the observer? ‒ Landscape experts versus novices • Influence of type of landscape? Experiment 3 ‒ Degree of urbanisation ‒ Landscape experts versus novices ‒ Predict viewing pattern? Eye Tracking for GeoDataManagement - Kristien Ooms 19

L ANDSCAPE PERCEPTION  Study Design Experiment 1 Focal Horizontal Vertical length view angle view angle a) Panoramic 50mm 70° 20,9° photograph b) Standard 50mm 31° 20,9° photograph c) Zoom 1 70mm 22,4° 15° d) Zoom 2 100mm 15,8° 10,5° e) Wide angle 18mm 75,1° 54,3° photograph 18 landscapes 90 photographs in total 23 participants (geographers) Eye Tracking for GeoDataManagement - Kristien Ooms 20

Homogeneous Heterogeneous Open Semi-open Enclosed 90 photographs in total 21 landscape expert participants 23 novice participants Eye Tracking for GeoDataManagement - Kristien Ooms 21

L ANDSCAPE PERCEPTION  Eye tracking technology • Non-portable RED-system (SMI)  Eye tracking experiments • Random order • 5 or 10 seconds per photograph • Free-viewing • Measured eye tracking metrics • Fixations: number, duration (ms) • Saccades: number, amplitude ( ° ), velocity ( ° /s) • Derived products: focus maps Eye Tracking for GeoDataManagement - Kristien Ooms 22

L ANDSCAPE PERCEPTION  Open  Panoramic  Less & longer fixations  More fixations  Less saccades  Shorter saccades Weaker visual exploration More information extraction  Shorter fixation duration  Homogeneous Easier information extraction  Less fixations  More saccades  Less & longer saccades  Larger saccades Weaker visual exploration  Faster saccades Stronger visual exploration Eye Tracking for GeoDataManagement - Kristien Ooms 23

L ANDSCAPE PERCEPTION Scan paths Expert Novice More Less fixations & fixations & saccades saccades Shorter Longer fixations fixations Longer Shorter scan scan path path Focus maps Smaller Larger visual visual span span Voronoi cells Larger Smaller Vorornoi Voronoi cells cells Eye Tracking for GeoDataManagement - Kristien Ooms 24

Saliency map Focus map 1050 x 1680 matrices Correlation between focus maps and saliency maps? Eye Tracking for GeoDataManagement - Kristien Ooms 25

I NFLUENCE OF W IND T URBINES ? Fanny Van Den Haute ▪ Sustainable energy >> wind turbines >> spatial planning Appropriate in the landscape? • • Visual impact? ▪ Research Questions • How do people look at a landscape with wind turbines? • Is there a difference before and after placement of the wind turbines? Is there a difference due to personal characteristics ( expertise )? • Does the type of landscape play any role in this? • Eye Tracking for GeoDataManagement - Kristien Ooms 26