cs5038 tom campbell 1 can web site consumer eye- movement analysis significantly benefit a web site...

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CS5038Tom Campbell

Can web site consumer eye-movement analysis significantly

benefit a web site business?

Tom Campbell http://www.csd.abdn.ac.uk/~tcampbel/

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Introduction

•What is eye-movement, and how do we track eye-movement—eye-tracking?

•What do we analyse with eye-tracking in relation to web sites?

•What results do we get?

•Is it all worth it?

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What is eye-movement, and how do we track eye-movement—eye-tracking?

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The retina

Fovea

Parafovea

Periphery

Perceive most detail

Rapid decrease in amount of detail

perceived

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The eye-tracker

Infrared light

(pointing down)

Eye Camera

(pointing down)

Scene Camera

(pointing ahead)

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corneal reflection

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The corneal reflections

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Example of scanpath

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Scanpath on commercial site

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Even other mammals’ eyes work this way!

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What do we analyse with eye-tracking in relation to web sites?

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The Eye-Mind Assumption

That there is a relationship between where we fix our gaze and what we are thinking about.

Caveat: however, we know that it is possible to look at one thing while thinking about something else, and that we are able to process information about things we see through peripheral vision.

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Web sites in particular…

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Goldberg & Kotval’s measures

Global search

Scanpath length

Spatial density

Number fixations/saccades

Number of backtracks

Local search

Average saccade length

Processing

Average fixation duration

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Objective usability evaluation

User testing

•Accuracy of responses

•Task times

Eye movement analysis

•Efficiency of search

•Ease of processing

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Measures often taken

Performance measures• Response Scores• Task Completion Times

Eye movement measures• Total fixation duration• Average fixation duration• Number of fixations• Spatial density of fixations

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What results do we get?

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Web sites in particular…

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What happened in general web page?

•Scan Patterns Were Similar in all areas

•Users don’t go to the Bottom often

•What Attracted Users – animations etc. borders,

•The Role of Peripheral Vision – users somehow determined if an ad interested them before they looked directly at it.

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Eye Trackers Can…

•Tell whether users are even looking at the screen.

•Tell whether users are reading or scanning.

•Learn the relative intensity of a user’s attention to various parts of a web page.

•Determine whether a user is searching for a specific item.

•Compare user scan patterns.

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Eye Trackers Can’t…

Let you know whether users actually ‘see’ something.(might not be aware of something they view)

•Prove that users didn’t see something. (eg. peripheral vision)

•Determine why users are looking at something.

•Test everybody. (some people have non-standard eyes!)

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Let’s look at some particular problems with the technology and how they might be corrected.

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Correcting data

Choose your criteria of Margin of error:

Accurate to within 0.30 degrees = 10 pixels

2 main possible types of error are:

• Absolute drift

• Relative warp

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Absolute drift

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Absolute drift (corrected)

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Relative Warp

most gaze points match the objects on screen, but some appear to miss their target.

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Filtering data

Areas of interest

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More specific study!

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An eye-movement study on ?

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Book Mark Finding of Alex Poole

Guidelines:• Basic• Information• 2 cues• Bottom-up

(Page title - site name)• Sort bookmarks by cue

Benefits:

Reduce frustration

Reduce search time

Reduce costs

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A commercial system!

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Eyetools: a commercial systemhttp://www.eyetools.com

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Eyetools: business model

You tell themyour target Demographics and the URL(s) to test

They collect data (1-3 days)

They discuss the results with you

http://www.eyetools.com

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Is it all worth it?

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Eye-tracking benefit

Does eye-tracking benefit commercial web-sites?If the site makes millions and eye-tracking shows obvious confusion areas. Then an improvement to the site will be financially rewarding. Perhaps the registration procedure is difficult to locate a serious flaw. This was the case with the smile internet banking site until eye-tracking identified the problem.

Evaluating the degree of interest in adverts according to varying factors seems also to be beneficial.

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What can you gain? •Increased profits. •Better user experience (less confusion).

What can you lose?•Cost of eye-tracking

•Opening up of business models to third party•Break up of synergy

•Relying on third party advice (which will be biased commercially)

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Conclusion?Probably depends on particular circumstances of the client’s web site.Money involved.

Number of users visiting.