Analyzing Eye Tracking Data - PowerPoint Presentation

Slide1

Analyzing Eye Tracking Data

MMC9503

Weimei SunSlide2

Outline

Introduction of Eye-tracking

Taxonomy of Eye Movements

Eye-tracking Techniques

The Data of Eye-tracker

Analysis of Eye-tracking Data

Eye-tracking ApplicationsSlide3

Eye-tracking

Eye-tracking is the process of measuring :

1. The point of gaze (where one is looking) or

the the “point of regard.”

2. The motion of an eye relative to the head. Slide4

Taxonomy of Eye Movements

Fixations

Fixations

are eye movements which stabilize the retina over a stationary object of interest.

Saccades

Saccades are rapid eye movements used in repositioning the fovea to a new location in the visual environment

.Both Fixations and Saccades are approximated by a linear, time-invariant system.Slide5

Eye-tracking Techniques

Electro-

oculography

(EOG)

Scleral contact lens/search coil

Photo-Oculography (POG) or Video-Oculography (VOG)Video-Based Combined pupil/corneal reflection Slide6

Electro-oculography

(

EOG)Slide7

Scleral contact lens/search

coilSlide8

POG or VOG

This category groups together a wide variety of eye movement recording techniques involving the measurement of distinguishable features of the eyes under rotation/translation.

E.g., the apparent shape of the

puil

, the position of the

limbus

, and the corneal reflections of a closely situated directed light source. Slide9

Video-Based Combined pupil/corneal reflection

It provides point of regard measurement. Slide10

The Data of Eye-tracking

Most current eye-trackers are based on video technology. They produce coordinates that indicate where the user is looking at using typically a sampling rate from 50 Hz to 250 Hz

Visualizing Eye-tracking Data

1. The most common way of representing eye-tracking data is to draw a scan path on top of the target image.

2. A time plot of the gaze dataSlide11

Scan Path

Fixations showed as circles

Saccades showed as lines connecting the circle

https://www.youtube.com/watch?v=

lo_a2cfBUGcSlide12
Slide13

https://www.youtube.com/watch?v=

zoLC0jjRcFUSlide14

Could you tell the

order

of the Areas of Interest (AOI)? Slide15

A time plot of the gaze data

This is a new technique that treats time as the prime attribute to be visualized.

The time plot of the gaze data

In

the visualization, the y- coordinate corresponds to the position in the result listing, and the x-coordinate is used to visualize the ordering in

time.Especially suitable for situations where (1) the exact locations of the fixations are less important than how they land on predefined areas of interest (AOI) in the stimulus; and when (2) the AOIs have a natural linear ordering. Slide16
Slide17

Analysis of

Eye

-tracking

Data

Interpret the visualization of gaze data

Collect all successive fixations to each AOI and calculate their cumulative fixation durationIdentify the time order of each AOI appearsInput the result into SPSS to do the related statistic analysishttps://www.youtube.com/watch?v=

SZZ9HfCxbG8Slide18

Eye-tracking Applications

S

ummary of eye-movement metrics and related usability problems, reported in the literature.Slide19
Slide20
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References

Duchowski

, A. (2007). 

Eye tracking methodology: Theory and practice

 (Vol. 373). Springer Science & Business Media.

Ehmke, C., & Wilson, S. (2007, September). Identifying web usability problems from eye-tracking data. In Proceedings of the 21st British HCI Group Annual Conference on People and Computers: HCI... but not as we know it-Volume 1

 (pp. 119-128). British Computer Society.Räihä, K.-J., Aula, A., Majaranta

, P.,

Rantala

, H., and

Koivunen

, K. (September 2005), Static visualization of temporal eye-tracking data.

In Proc. INTERACT Rome.

Young, L. R., & Sheena, D. (1975). Survey of Eye Movement Recording Methods.

Behavior Research Methods & Instrumentation, 7

(5), 397-439.Slide23

Thank You

MMC9503

Weimei Sun